Plat Tech - Prelims

input

The information the computer receives from the user is called

Early computers

designed only to interact with text commands. Users had to know the specific commands to type to get the computer to do what they wanted

mouse

more human-friendly graphical style, the primary way to input data

touchpads or trackballs

came out as a more precise alternative to early mouse devices. Another popular input device

stylus

allows people to write on certain device screens

Garbage In, Garbage Out

, the programming community was using the phrase _. This means that a computer, or a computer program, can only work with what humans give it.

output

The information the computer returns to the user is called

Monitors, or screens

are a very common way for computers to show us information

Screens

used in lots of ways: projectors for watching movies on a big screen, and smartphones for keeping in touch with friends. Screens are essential for humans to use computers.

3D printers

which people use at home and in industrial settings, can make models out of plastic, resin, or other materials.

peripherals, or peripheral devices

In the world of information technology (IT), devices such as printers, screens, and speakers are called _.

is something outside the main computer that can be connected with a cable or wirelessly

Processing

occurs when a computer's central processing unit (CPU) determines what to do with the input. It takes the tap on the screen, the instructions, and runs through all the steps and options available to show the text messages

software

The programs and the system that run the computer are called

hard drive

They all get saved in a special part of the computer called the

persistent or mass storage

Hard Drive - This part keeps everything safe even when the computer is turned off, which is why it is called _

Hard Disk Drives

store data on special magnetic disks inside a protective housing. Because a hard disk drive is usually installed inside a computer, it is not easy to move it to another computer

Solid-State Drive

stores information using flash memory, which lets it work much faster than an HDD.

Flash memory

holds onto information even when there is no power, but it can be reprogrammed with new data very quickly.

flash drive or an external hard disk

plugs into the computer with a USB cable can be used if files need to be carried around. Hard disks can keep a lot of information and do not cost very much. However, they might stop working if they are bumped or moved around too much, as they have moving parts

Optical drives (ROM)

like CD-ROMs, DVDs, and Blu-ray discs can also store things on devices by plugging them into the computer. These are good for keeping things like videos, pictures, papers, or a company's financial details, but usually not for programs or apps. Optical storage is good for holding data but not great at adding new data.

Random Access Memory (RAM)

like a temporary shelf where programs, data, and the operating system currently in use are kept. This kind of memory is "volatile" because it changes easily; it is not stable. When the computer is turned off, everything on this shelf gets wiped clean. This is different from the hard drive, which is like a long-term storage box meant to keep data safe forever.

Apps

began emerging in the 2000s and have become a multibillion-dollar industry. Just like software for computers, mobile apps include productivity tools, social media, and games. These are designed to work better on mobile devices, which have smaller touchscreens.

Social media

are also very popular on mobile devices. Sharing stories and pictures with friends and family, or commenting on a classmate's status, becomes possible

Mobile games

fun, simple ways to pass the time, and navigation apps help us avoid getting lost.

banking

is made easy by making financial information available on a bank's finance app.

Linux computers

computers usually come pre-installed with Mozilla Firefox. But the most popular browser by far is Google Chrome.

Chrome

the most popular browser because it used to be faster and had more features. Modern browsers generally have all the same features. Whatever browser you use, it is almost certainly going to be the most used piece of software on a computer.

Safari

only available on Apple devices. An account linked to a browser will sync the settings and bookmarks. With smaller screens on mobile devices, scrolling is more common to view a web page, which can be tiring. Also, the touch interface, which is the main way to interact, can be less precise, making some webpages harder to navigate.

Microsoft Outlook

It was released in the 1990s and is part of the Microsoft Office suite, which also includes Microsoft Word, Excel, PowerPoint, and other Microsoft productivity tools.

Instant Messaging (IM)

software lets people talk to each other in real time. Unlike email, there is virtually no delay between sending and receiving a message.

WhatsApp

owned by Facebook. It is popular globally because it allows sending texts worldwide without incurring international charges. Cellphone carriers usually tack on extra fees for anything international.

collaboration software.

Instant messaging on desktop computers is making a big comeback thanks to

Software

A set of instructions that tells a computer what to do. The computer's operating system (OS) reads and follows these instructions. It is important to know that application software is made for a specific operating system.

Productivity Software

A term that encompasses applications that enhance productivity, both personally and professionally, with tools and features that streamline and automate tasks. These applications include collaboration software that allows more than one person, often teams, to work together on the same information to complete tasks

Commercial Software

A good example of productivity software is the programs in the Microsoft Office suite. The Office suite has Microsoft Word for creating documents and Excel for creating spreadsheets. It also includes tools like PowerPoint for presentations and Outlook for email. To stay competitive, Microsoft introduced online versions of their software as well. They gave them similar designs and layouts, so there is not much of a learning curve.

Free Software

Google has a suite, too. Google's is similar to its online competitor, Microsoft Office, with free versions of word processing and spreadsheet tools. One of the best features of the Google suite is the ability to work together on a single document as a team. It allows creating and sharing the document with others, who can edit it in real time. This back-and-forth collaboration can go on until the document is just right.

There are also free software packages from companies that make open-source software. Two (2) of the most popular ones are OpenOffice and LibreOffice. These have a similar feel to Microsoft programs, which makes it easy to switch over.

Collaborative Software

helps everyone work together effectively with technology. The goal is to make it easy for groups to focus on a shared objective or task. This is especially important today, when it is more common for coworkers and classmates to be in different locations.

Communication Apps

There are many software tools available for improving teamwork, such as Slack, Microsoft Teams, Google Workspace, and more. The essential features of these apps are instant messaging and video conferencing, which make remote work much easier.

These apps are crucial for filling in that face-to-face communication gap. A Zoom call can replace a meeting in the conference room, and a team Slack channel can substitute for the water-cooler talk that lets coworkers get to know each other.

Remote work saves companies money by reducing the need for office space and personnel, so even though it is a little more complicated, it is in their interest to find ways to replace the interpersonal communication that used to happen at the office and keep everyone feeling involved.

File Sharing

: An early part of working together online was file sharing. A file can be uploaded to a cloud storage service and then emailed to someone so they can access it. Services like Dropbox, OneDrive (formerly SkyDrive), and iCloud have been offering this for over a decade. They let you store a limited number of files for free, but for more space, a monthly subscription is required.

Work Management Software

It allows people to collaborate by working together on different parts of a project, but it has features that differ from other kinds of collaboration software. Work management software allows employees, freelancers, and other project teammates to coordinate their work to meet a specific goal on a deadline.

Some of the more popular platforms include Monday.com, Trello, Jira, and Basecamp. All of them have a free version, but it limits the number of users and restricts some features.

Remote Assistance Software

This is powerful software because it allows you to see and control another computer as if it were sitting right in front of you. "Remoting" allows using a keyboard and mouse to work with any program, file, or setting, and even to send files back and forth.

Technicians use this software to troubleshoot and help people with their computer problems. It is easier for them to fix the issues by taking control of the computer rather than explaining the steps over the phone. Plus, the person being assisted can watch the technician work, which can help them feel more comfortable fixing the problem on their own next time. The only thing this software cannot help with is if the user does not have Internet access.

Word processing

the technical term for creating digital documents, like one would with pen and paper or an old-fashioned typewriter.

word processor

a common computer program that helps type up and format reports, letters, essays, and more.

Word Processing Software

Word processing has existed on computers for nearly as long as computers have been around, which shows how vital it is for human beings to have a way to write and send documents to each other. Over time, these programs have become more advanced, but the core tasks remain the same: reading, writing, formatting, and editing text.

The most popular word processing program is Microsoft Word. You do need to pay for a license to use it, but Word is one of the most powerful word processors out there. It has features that allow you to do everything from basic text formatting to creating advanced indexes and spell-checking.

Spreadsheet Software

Spreadsheets are those square grids of rows and columns that store data and, most importantly, calculate it. Learning to use spreadsheet software will give an extra boost in the modern world.

These programs have powerful tools for searching, sorting, creating formulas, and performing math. Spreadsheets are often used for statistical analysis and financial information. One of their best features is the ability to sort data in multiple ways, which helps make large amounts of information easier to understand. Spreadsheets can also turn data into tables, charts, and graphs to make it easier to understand.

Presentation Software

Digital presentation tools to help demonstrate ideas people want to get across. These tools allow you to add visuals to presentations using slides. Slides are like individual pages shown on a screen for the audience to see while the presenter talks about their topic. They can include animations, pictures, charts, and data. A good set of slides makes a presentation more interesting and memorable.

Diagramming and Graphics Software

Used to make visual representations of projects, especially diagrams. For example, flowcharts that illustrate a project's steps so a team can better understand the process. Some of this software is used in IT departments to create network diagrams for large networking projects. Diagrams are great for helping everyone understand the structure of a project or task, and stay on the same page.

Digital Whiteboards

Online whiteboards are perfect for brainstorming together as a team. Miro is an example of an online workspace where everyone can add to team whiteboards. It does not have to be just text; it can include pictures, videos, and links to other websites. Miro's goal is to make remote work as productive and collaborative as face-to-face work. It also works well during remote learning in schools because teachers and students can work on the whiteboards as if they were in the classroom.

Digital Imaging Software

Imaging software is a type of computer program that helps take, edit, and process digital pictures. One important thing to understand about imaging software is how it saves pictures on devices.

Common tasks include cropping, resizing, rotating, recoloring, erasing parts, and touching up to remove blemishes. The software allows you to preview changes and compare the original image with the edited version before saving. Adding text, changing the font, and adjusting the color, size, and formatting are possible.

Video Software

: Creating videos used to be expensive and hard to do. But with digital video editing software, anyone can be their own movie director, producer, and cinematographer. There are many options available for video editing software—from professional ones like Adobe Premiere, Final Cut Pro, and DaVinci Resolve to free options like DaVinci Resolve Free Edition, iMovie, and Microsoft Clipchamp.

There are also many video editing options for smartphones. Some come with the phone, and others can be downloaded from the App Store or Play Store. Some social media platforms even have built-in video editing tools. Editing videos on a mobile device is limited compared to on a desktop, but it is a nice way to quickly touch up a video.

operating system (OS)

a piece of software that manages computer hardware and software resources, and provides common services for computer programs

command line interface (CLI) or a graphical user interface (GUI).

Users interact with an OS through either a

Ease of Use

: An operating system creates an environment where different software applications can run. The application software is the program or group of programs that lets users accomplish different tasks, like browsing the web, sending emails, or designing graphics.

Because of the OS, software developers do not need to worry about writing code to access the hard disk or to send a graphic to a printer; they can rely on the OS to do these things for them. The OS acts as a go-between for the hardware and applications, letting developers focus more on improving programs or building better pieces of hardware.

Managed Drivers

Another core function of an operating system is to "drive" the computer hardware and manage system utility applications. A "driver" is a piece of software made to control a specific piece of hardware on a certain OS. For example, a printer will have a driver for that specific model, and that model will have drivers for different operating systems like Windows, macOS, and Linux.

Processing Instructions

One fundamental difference between operating systems is the number of instructions that the central processing unit (CPU) can handle. This difference applies to the OS, too.

Computer hardware and software are designed to operate with either 32 bits or 64 bits of instructions at one time (and that "one time" is as short as one billionth of a second). Operating systems work similarly, able to manage 32 bits or 64 bits at one time. As systems have advanced, 64 bits has become the standard size for today's CPUs and OSs.

Embedded Operating Systems

A low-cost operating system that uses few system resources and is made for a single purpose. These special computers and their OS are often optimized for real-time processing.

Open-source

means that the code used to create a piece of software is available for anyone to look at and use. It does not always mean that the software is free (though many are), but it does mean that developers can change how the software works, as long as they make the changes available to everyone else in turn.

Linux

is an open-source OS created by Linus Torvalds in the early 1990s. comes from combining his name, Linus, with "UNIX," the system he was building on. Linux followed the same design structure: a multi-user and multitasking environment.

Open-Source Operating Systems

The open-source model makes software creation faster and better managed, considering how many hands a program might pass through.

Commercial Operating Systems

A type of operating system that requires a purchased license to install and use—generally on only one (1) device. Commercial OS code is also kept secret by the developing company, rather than shared out like open source code. Some products are more flexible than others about the "one license, one device" rule, but Windows (by far the most popular desktop operating system in the world) is very specific. Users must have purchased a license to install and use Windows on their machine, and it cannot be shared.

Windows

Microsoft does not release major updates to its Windows operating system regularly. For example, there were almost six years between Windows XP and Windows Vista, but only two (2) years between Vista and Windows 7. The main reason for the quicker update was that many people did not like Vista. After Windows 7, Microsoft released Windows 8, then Windows 10, and now Windows 11. Each new version of Windows comes with new features and better security. Many of the behind-the-scenes tools in Windows look and work the same, while the main desktop always gets a new look with the new version.

Apple macOS

Apple is very consistent with their macOS updates—a new version every autumn. For many years, they named their OS versions after big cats, like Cheetah and Snow Leopard. When they ran out of cat names, they started naming them after famous places in the western United States, like Ventura and Catalina.

Text-Based Operating Systems

: Use a command line interface (CLI). To interact with the system, users type commands into the console, which is just a plain screen or a window that accepts characters from the keyboard. This is how users can manage files, run programs, and change settings. Unlike the systems most people are probably familiar with, this one does not use a mouse with a CLI because there are no icons to click.

distributions or distros

The most popular text-based operating systems are part of the open-source Linux family. There are hundreds of different versions, called

Ubuntu

The most popular Linux OS is _ , which has been around since 2004. It is free and is popular for servers and cloud apps. Other well-known Linux distributions include Debian, Red Hat, and Mint.

Scripting

Another key benefit of a CLI. Scripts are small programs that quickly execute instructions, saving the user time and effort. Users can also use a CLI system for remote management, making it possible to control computers from a distance.

Graphical User Interface

· is now the norm for almost all computers and devices, as they are user-friendly and easy to follow, so people of all ages can grasp how they work.

Tablet Use

Tablets could only exist with icons and a touchscreen. Apple's iPads set the standard for tablets with several notable features. Most tablets will have easily understandable icons, which users can manipulate using a stylus or the touch of a finger, set against a high-resolution display. This makes tablets easy to see in a variety of conditions.

Visual Applications

The Apple Vision Pro headset has added a third input method: the eyes. Users can look at an icon in their field of vision and pinch their fingers together to let the OS know that they are selecting the item they are looking at. This works the same as clicking an icon with a mouse or touching an icon with their finger on a touchscreen.

ChromeOS

A popular visual operating system that relies heavily on the browser is Google Chrome's operating system, ChromeOS, which is only for Chromebooks.

To use this a Google account and an Internet connection are needed to sign in. There is a guest login option, but any settings or personalization will be reset when users log out or restart the Chromebook. Because it is a cloud-based operating system, it works best when connected to the Internet. It boots up faster than a traditional operating system because it does not have as much software to load. Moreover, its built-in security makes web browsing safer.

Memory

hardware component that stores data, instructions, and information temporarily or permanently for processing. It consists of an array of bytes or words, each with a unique address. Memory is expected to hold both input data and program instructions needed for the CPU to execute tasks and to provide quick access to data being used.

Main Memory

Also known as RAM (Random Access Memory), it is a large array of bytes or words that the computer's processor uses to store programs and data that are actively being processed. It is volatile, meaning that all data is lost when the power is turned off

Logical Address

Also known as the virtual address, which is an address generated by the CPU. Logical address space can be defined as the size of the process. A logical address can be changed.

Physical Address

Also called a real address, which is generated by the Memory Management Unit (MMU) through run-time mapping of virtual addresses. It is the set of actual addresses used by the memory hardware. Unlike virtual addresses, physical addresses remain constant

Static Loading

All about loading the entire program into a fixed address. It requires more memory space.

Dynamic Loading

All about loading program routines into memory only when they are needed. This saves memory by not loading unused routines. The routines remain on disk in relocatable (can be loaded at any memory location) format until called. It allows better memory utilization, especially for large programs

linker

program that takes one or more object files generated by a compiler and combines them into a single executable file.

Static Linking

linker combines all necessary program modules into a single executable program. So there is no runtime dependency. Some operating systems support only static linking, in which system language libraries are treated like any other object module.

Stub

is a small piece of code. When executed, it checks whether the needed routine is already in memory. If not, then the program loads the routine into memory.

Monoprogramming

This is the simplest memory management approach. Memory is divided into two (2) sections: one part for the operating system. The second part is the user program.

Multiprogramming

A memory partition scheme with a fixed number of partitions was introduced to support multiprogramming. This scheme is based on contiguous allocation wherein:

o Each partition is a block of contiguous memory.

o Memory is partitioned into a fixed number of partitions.

o Each partition is of fixed size.

partition table.

Once partitions are defined, the operating system keeps track of the status of memory partitions through a data structure called a

Contiguous Memory Allocation

A memory management method where each process is given a single, continuous block of memory. This means all the data for a process is stored in adjacent memory locations.

Non-Contiguous Memory Allocation

This method allows processes to be broken into smaller parts, which are placed in different, non-adjacent memory locations. Techniques for non-contiguous memory allocation include

Paging

: The process is divided into fixed-size blocks called "pages," and the memory is divided into blocks of the same size called "frames." The operating system keeps a page table to map logical pages to physical frames.

Segmentation

The process is divided into segments of varying sizes, such as code, data, stack, etc. The operating system maintains a segment table to map logical segments to physical memory.

Fixed Partition Allocation

Memory is divided into fixed-sized partitions, and each partition can hold only one process. The OS keeps track of free and occupied partitions using a partition table.

Dynamic Partition Allocation

Memory is divided into variable-sized partitions based on the size of the processes. This helps avoid memory wastage but can result in fragmentation.

Placement Algorithms

When allocating memory, the OS uses placement algorithms to decide which free block should be assigned to a process:

First Fit

Allocates the first available partition large enough to hold the process.`

Best Fit

o Allocates the smallest available partition that fits the process, reducing wasted space.

Worst Fit

Allocates the largest available partition, leaving the largest remaining space.

Next Fit

Similar to First Fit but starts searching for free memory from the point of the last allocation

Swapping

This moves processes between main memory and secondary memory to manage limited memory space. It allows multiple processes to run by temporarily swapping out lower-priority processes for higher-priority ones. Processes moved to disk are not deleted. They are only temporarily stored outside RAM until the CPU needs them again. The swapped-out process resumes once it is loaded back. Transfer time depends on the amount of data swapped.

Fragmentation

Happens when a process is loaded and removed from memory after execution; it creates a small free hole. These holes cannot be assigned to new processes because they are not combined or do not fulfill the memory requirement of the process. In operating systems, two types of fragmentation are:

Internal Fragmentation

Happens when a process is allocated a memory block that is larger than what it needs, causing unused space inside the allocated partition.

External Fragmentation

Happens when free memory is split into many small blocks scattered throughout memory, making it difficult to allocate large processes even if the total free memory is enough.