Operating System Prelim

computing cycle

the set of steps the device takes to understand what it needs to do and then process it.

Input

The information the computer receives from the user. Computers need humans to tell them what to do. The computing cycle starts by giving device instructions. Putting information into a computer, or providing input, can happen in many ways.

Input Devices

Modern examples include a keyboard, a mouse, touchscreens, and cameras. All these options are available to us today, but this hasn't always been the case.

Input Quality

As early as 1957, the programming community was using the phrase "Garbage In, Garbage Out" (GIGO). 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

Output Devices

Monitors, or screens, are a very common way for computers to show us information.

Processing

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.

How Processing Works

Input comes to the CPU from many different sources. At the same time, text messages are opened, another app might let the CPU know that there is an update available, there could be an incoming email, the calendar app could alert about an appointment, and somebody could be calling.

Storage

It is like a big box where all the computer programs and information are kept.

software.

he programs and the system that run the computer are called

hard drive

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

persistent or mass storage.

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

Storage Devices

The two most common ways to store information on a computer for a long time are Hard Disk Drives (HDDs) and Solid-State Drives (SSDs).

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

that 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. Hard disks are manufactured in 2.5-inch and 3.5-inch sizes, which are their form factors.

Optical drives

like CD-ROMs, DVDs, and Blu-ray discs can also store things on devices by plugging them into the computer.

Read-Only Memory (ROM)

Optical storage is good for holding data but not great at adding new data. Originally, they were designed to just hold data and were known for their

Memory

It is important to understand the differences between storage and memory. They mean different things and relate to different kinds of equipment.

Common Applications

Common software applications are programs designed to perform specific tasks for users. The software used every day includes web browsing, email, and messaging applications.

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.

entertainment

Streaming video and audio from phones lets us access movies, TV shows, and songs.

Social media

apps 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

are 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. Many large companies will have their own apps as well, making it easier for customers to use their services.

Web Browsing Applications

Every device with an operating system (OS) comes bundled, or pre installed, with a browser from that OS's parent company. A Windows computer has Microsoft Edge. Apple devices like Macs, iPhones, and iPads come with Safari. Linux computers usually come pre installed with Mozilla Firefox. But the most popular browser by far is Google Chrome.

Smartphone Browsers

Smartphones come with a browser too, but people do not use them as much as they do on a computer because many other apps compete for their attention. The major browsers on a PC, like Chrome, Edge, and Firefox, are also available for Android and iOS.

Email Applications

The most commonly used email software is 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.

Messaging Applications: 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. Basic IM software nowadays allows users to send text messages, photos, and files between smartphones with ease. It is popular because it is usually free and self-explanatory.

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.

Types of Productivity Software

1. Commercial Software

2. Free Software

3. Collaborative Software

4. Communication Apps

5. File Sharing

6. Work Management Software

7. Remote Assistance Software

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.

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.

Collaborative Software

Collaboration just means working together. Collaboration 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.

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.

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.

Work Management Software

Some software types fall into more than one category. Work management software is one example. 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.

Remote Assistance Software

There are several remote assistance software options for Windows PCs, like AnyDesk, TeamViewer, and Quick Assist (which is built into Windows). This is powerful software because it allows you to see and control another computer as if it were sitting right in front of you.

Productivity Software Tools

1. Word Processing Software

2. Spreadsheet Software

3. Presentation Software

4. Diagramming and Graphics Software

5. Digital Whiteboards

6. Digital Imaging Software

7. Video Software

Word Processing Software

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

word processor

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

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.

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.

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.

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.

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.