IT CSEC STUDY GUIDE

Information Technology

Information Technology

The use of hardware and software equipment to access, retrieve, store, manipulate, and present data and information.

Types of Computer Systems (from fastest/most storage/least portable) and examples of each

Super Computers (Cray)

Mainframes (IBM zEnterprise Systems)

Desktop systems

Mobile devices (notebook, netbook, phone, Nintendo switch)

Embedded devices (microwave, air fryer, remote control, car ignition systems, ATMs)

embedded devices

devices with fixed-in, built-in processors that activate when a button is pressed

define the 4 main components of a computer system

input: the process of taking information from the physical world and entering it into a computer

processing: the manipulating of data into information

output: the projection of processed data (information) in audio or visual format

storage: the keeping of information temporarily or permanently for future use

2 types of storage

primary storage

secondary storage

2 types of primary storage

RAM

ROM

RAM

random access memory; located on the motherboard for quick access and it temporarily stores data that is being used during processing

volatile

ROM

read only memory; located on the motherboard, permanently stores the instructions for the operating system and stores the BIOS

non-volatile

3 types of secondary Storage Devices

magnetic

optical

flash-memory (hybrid)

magnetic storage devices

• hard drive

• floppy disk

• zip disk

• magnetic tape

optical storage devices

• Compact Disk

• Digital Video Disk

• Blu-Ray

flash memory devices

USB flash drive

memory card

Units of Storage (and their values)

Bits - 0 or 1s

Bytes - 8 bits

Kilobytes - 1024 bytes

Megabytes - 1024 kilobytes

Gigabytes - 1024 megabytes

Terabytes - 1024 Gigabytes

interrelation of the major hardware components of a computer system

a computer cannot process data if no data has been input, a computer cannot output information if no data has been processed, a computer cannot store information if no information has been input, etc.

local storage

storage devices that are physically connected to a computer

cloud storage

a module in which data is stored on remote servers over the internet

Cloud Storage vs Local Storage (Capacity, Cost, Accessibility, Security)

Capacity

• local storage: Fixed capacity

• cloud storage: easily expandable capacity

Cost

• local storage: one-time purchase

• cloud storage: usually a subscription

Accessibility

• local storage: accessible as long as you have the device

• cloud storage: accessible as long as you have internet and a password

Security

• local storage: vulnerable to theft, once the device is damaged it stays damage. protected by physical measures such as safes

• cloud storage: encrypted data, password protected, still at risk of corruption or viruses or even leakage of data

advantages and disadvantages of using cloud storage

Advantages

• can share and sync files

• can be accessed anywhere with internet

• can be easily expandable

• files are encrypted

Disadvantages

• internet dependent

• don’t have true ownership of your data

• might get expensive over time

advantages and disadvantages of local storage

Advantages

• internet independent

• fixed cost, one time purchase

• accessible anywhere as long as you have the device

Disadvantages

• vulnerable to theft and environmental conditions

• device damaged, stays broken

• fixed storage, not expandable

types of input devices

manual input devices: devices which involve manually inputting data into the computer

direct data input devices: devices that automatically enter data into the computer

categorize these devices as manual or direct

OMR, OCR, MICR

mouse

joystick

barcode reader

document scanner

light pen

touch terminals

voice response unit

touch screens (ATM, point of sale)

keyboard

camera

biometric system

sensors

remote control

sound capture

webcam

OMR, OCR, MICR - direct

mouse - manual

joystick - manual

barcode reader - direct

document scanner - direct

light pen - manual

touch terminals - manual

voice response unit - manual

touch screens (ATM, point of sale) - direct

keyboard - manual

camera - manual

biometric system - direct

sensors - direct

remote control - direct

sound capture - direct

webcam - direct

the 3 types of digital scanners

optical mark recognition: scans and relies on precisely positioned marks on a page

optical character recognition: scans hard copy text to make it soft copy

magnetic ink character recognition: reads a special type of magnetic ink on bank checks

types of output devices

visual output: monitors

audio output: headphones, speakers

system software

software that is responsible for the efficient functioning and maintenance of a computer system

types of system software

operating system

utility software

operating system

software that governs how other software and hardware function

functions of an operating system

• provides a user interface

• provides security through authentication

• file management

• memory management

• process management

• device management

utility software

software that is responsible for the maintenance of the computer system

types of utility software

• Disk Defragmenter

• Disk Cleaner

• Registry Cleaner

• Antivirus Programs

• Firewall programs

• Backup and Restore Programs

application software

software designed for a specific task or program that helps to solve end-user problems. also known as end-user programs

types of application software

general purpose/off the shelf

custom general purpose

specialized

custom written/tailor-made/bespoke

integrated

types of general purpose application software

word processing

spreadsheet

database management

communication

presentation

graphics

user interface

the part of the computer that interacts with the user

types of hardware and software interfaces

Hardware (touch screens, specialized keyboards, sensors),

Software (Command line, Menu-driven, Graphical user).

advantages and disadvantages of CLI

advantages

• shortest processing time

• the quickest to operate if the commands are known

disadvantages

• hard to learn

• not user friendly, user has to remember all the commands to move efficiently

• limited choice in input devices

advantages and disadvantages of Menu driven interface

advantage

• more user friendly than CLI, user no longer has to memorize commands

• variety of input devices can be used

disadvantage:

• still need to know where different things are located to move efficiently

• slower to process than CLI

advantages and disadvantages of GUI

advantages

• very user friendly

• variety of input devices can be used

disadvantages:

• slowest to process

4 things you should do before trouble shoot

1. restart/refresh

2. document error codes

3. take note of previously done steps

4. check the cables

types of troubleshooting Hardware Problems

Cable problems

Monitor problems (HDMI/VGA)

Printer problems

Battery problems

types of cable problems

cable loose

cable faulty

extension cord not turned on/faulty

types of monitor problems

monitor brightness too low

monitor not turned on

hdmi/vga cable loose, faulty

power surge

printer problems

ink cartridge empty

paper finished/jammed

driver not updated

wrong printer selected

wireless printer not connected to wifi/bluetooth

battery problems

battery dead

Data

Raw, unprocessed facts

Information

Processed data

Data processing

Manipulation of data to obtain information

Information system

Any record keeping system (manual or digital)

Source document

A document used to collect, store, and share information

Turnaround document

A printed document with machine-readable information that needs to be added to by a human before processing

Human-readable

Hard copy texts that can be understood by a human

Machine-readable

Soft copy documents that can be understood by a computer

Hard copy

Information output onto paper, tangible and permanent

Soft copy

Information output on a screen, intangible and accessed on a computer

Relevancy

Information should be what the user is looking for and up to date

Currency

Information should be relatively recent with working links

Author/Credibility

Consider the author's credentials and authorization to provide information

Bias

Determine if the author is stating facts or opinions

Validation

Computerized process of checking data to ensure the data makes sense, does not test for accuracy

Verification

Human process of checking data for errors

Length check

Checks if the data is the appropriate length

Range check

Checks if the data is within the appropriate range

Reasonableness check

Checks if the data is reasonable

Format check

Checks if the data is in the correct format

Data type check

Checks if the data is the correct type

Consistency check

Checks if two fields match or have discrepancies

Presence check

Checks if data has been entered into a field

Double-data entry

Entering data twice by different people to check for accuracy

Proofreading

Checking data for accuracy by reading it over

Sequential file organization

Data stored in a sorted order based on one or more fields

Serial file organization

Data stored in the order it is entered

Direct file organization

Data stored in the order it is entered, with direct access using a key

Batch processing

Processing large amounts of data automatically

Transaction processing

Data transferred between two or more computers

Distributed processing

Processing shared between multiple computers on a network

Online processing

Data transfer or processing that occurs over the internet

Real-time processing

Processing data that requires immediate response

Local area network

Network that connects devices in a small geographical area

Wireless local area network

Network that connects mobile devices wirelessly

Metropolitan area network

Network smaller than a WAN but bigger than a LAN, connects devices within cities

Wide area network

Network that connects devices over a large geographical area

Peripheral area network

Network that connects mobile devices wirelessly over a small geographical area

characteristics of 2G network

• poor calling quality that was unencrypted

components of telecommunication

message

sender

receiver

medium

protocol

protocol

a set of explicit rules and regulations that govern the way files are sent and received over the internet

characteristics of a 3G network

• internet

• call quality improved

• encrypted calls

• caller ID

characteristics of a 4G network

• video downloading

• picture sharing

• email

• better quality calls

characteristics of a 5G network

everything 4th gen but faster

Standalone computers

Computers not attached to a network

what type of waves are used for mobile network communication

Communication relies on radio waves and microwaves for transmitting and receiving signals

2G

Calling with bad call quality and security

3G

Encrypted calls, caller ID, SIM card, internet access with improved call quality and security

4G

Picture sharing, video downloading, web browsing with faster network coverage

5G

All features of 4G but even faster network coverage

network

a group of nodes (devices) connected together by communication media that allows information and other resources to be shared

node

any device on a network capable of sending or receiving information

benefits of a network

• sharing information

• sharing resources

• used in various industries

• saves costs

wired communication media

twisted pairs

coaxial cables

fibre optic cables

twisted pairs and coaxial cables are made of _________

fibre optic cables are made of _______

copper, glass

twisted pairs are ______band and coaxial and fibre optic cables are _____ band

voice, broad

advantages of fibre optic cables

• able to transmit data over long distances

• able to transmit data quickly

• doesn’t interfere with any other networks

• moisture and lightning resistant