device: beeper/loud speaker
use: to indicate barcode correctly read/error in reading barcode
device: (LCD) screen/monitor
use: to show prices and other information about goods
device: touch screen
use: to show prices and other information about goods/to select items that need to be
weighed/identified
device: weighing machine
use: to find weight of loose items (e.g. fruit) to enable pricing
device: (magnetic) card reader/CHIP and PIN reader
use: to read customer’s debit/credit card/enable customer to pay for goods using a
credit or debit card
device: printer
use: to print receipts

Bridge: Joins together two networks that use the same base protocols.

Hub: Copies all packets of data to all devices on the network.

Router: Stores the addresses of computers on the network and transfers data between devices.

Switch : Analyses each data packet and sends it to the computer it was intended for.

A computer virus is a program designed to damage other programs or causes irregular behaviour in a computer system.

• Passive matrix create images by scanning the entire screen whereas active matrix displays are made using thin-film transistors technology(TFT)
• active matrix  display has a higher resolution compared to passive matrix
• Active matrix consume more energy than passive matrix

• (Cache) Stores regularly accessed instructions/data
• Reduces the need to access instructions/data from the main memory
•  Makes up for the difference in speed of the CPU and main memory

1. Use a humidifier: Using a humidifier can help maintain a consistent level of humidity in the computer lab, which can prevent the negative effects of low humidity.

2. Avoid dry air: Avoid creating a dry environment in the computer lab by opening windows or using fans to increase air circulation.

3. Regular maintenance: Ensure that all computer components are properly maintained and cleaned to prevent damage due to static electricity.

4. Backup data: Regularly backup all important data to avoid data loss in case of hardware failure caused by low humidity.

5. Monitor humidity levels: Use a hygrometer to monitor the humidity levels in the computer lab and take corrective measures if the levels fall below a safe range.

6. Use anti-static materials: Use anti-static mats or wristbands when handling computer components to prevent static electricity buildup.

• Software may be designed to run on 1 core and not multiple cores
• depends on the task(s)  i.e some tasks cannot be split across cores
• Clock speed also affects speed i.e dual core may have a faster clock speed and quad-core may have slower clock speed so one task may be run faster/slower
• RAM size also affects speed i.e Quad-core may have less RAM  amount of VM being used
• Cache size also affects speed i.e Quad-core may have less cache

(a) Pointer

•  A graphical object on a computer screen that responds to move movement and allows the computer user to select and execute commands in graphical user interface operating systems

(b) Desktop

• It Is a special folder in the file system that is displayed when no other windows are open

1. Overheating: Smoke and dust particles can accumulate inside the computer's casing, blocking airflow and hindering the cooling mechanisms of the computer. This can lead to overheating of the internal components, such as the CPU and graphics card. Overheating can cause system instability, performance degradation, and even permanent damage to the hardware.

2. Component Malfunction: Smoke and dust particles can settle on electronic components, such as the motherboard, memory modules, and connectors. Over time, this accumulation can create a layer of debris, leading to poor electrical contact and interference with signal transmission. This can result in component malfunctions, intermittent failures, or even complete hardware failure.

3. Short Circuits: If smoke or dust particles contain conductive materials, such as metal flakes or moisture, they can create a risk of short circuits. When conductive particles come into contact with exposed circuits or connectors, they can cause a direct electrical connection between two points that are not intended to be connected. Short circuits can damage components, disrupt data transmission, and even pose a fire hazard.

4. Increased Maintenance Requirements: Smoke and dust particles can increase the frequency and complexity of computer maintenance. Accumulated dust can clog cooling fans, causing them to work less effectively or even fail. Additionally, smoke particles can leave behind sticky residues that further attract dust, making the cleaning process more challenging.

5. Reduced Performance and Reliability: As smoke and dust particles accumulate within the computer, they can restrict the movement of mechanical components, such as fans or disk drives, affecting their performance and reliability. Dust particles can also hinder the reading and writing capabilities of optical drives or cause errors in data transmission.

• Knowledge base – is the systems’ database of knowledge about a particular subject. It contains relevant facts, beliefs, assumptions and procedures for solving a particular problem
• Inference engine – this is the software that controls the search for knowledge in the knowledge base and produces conclusions. It takes the problem posed by the user and seeks to analyze it in order to arrive at a conclusion.
• User interface- this is the display screen that enables the user interact with the system.

Syntax
• An error that occurs when a command does not follow the expected syntax of the language, e.g. when a keyword is incorrectly spelt
• Incorrect: IF A ADN B Then
• Correct: IF A AND B Then

Logical
• An error that causes a program to output an incorrect answer (that does not necessarily crash the program)
• An algorithm that calculates a person’s age from their date of birth, but ends up giving negative numbers

• more accurate/improved stock control/recording system/automatic
• reordering/automatic updating of stock file
• less staff/wages needed
• sales statistics now available
• faster throughput
• itemised receipt
• records every transaction
• records staff work rates
• less pilfering by staff/easier to identify pilfering
• less errors
• faster calculations
• links to EFTPOS

• an use Internet connection and telephone at the same time
• much faster data transfer speed
• always “on”
• charged for number of bytes/flat rate per month rather than actual time on line
• more bandwidth

• URL is clicked/typed into a web browser address bar. The page is requested (by the web browser) so HTML and files are fetched from a web server and the browser collates the page, which is then displayed on the monitor.
• OR
  URL is clicked/typed into a web browser address bar (1). The browser locates the IP address either in cache or using a DNS server and the browser sends a request to the web server with that IP address web server uses HTTP to send back the requested web page and the browser displays the content of the page .

• Real time  E.g. turning the wheel must turn the car immediately
• On line - Otherwise system cannot be real time

• A compiler translates the whole program in one go whereas An interpreter translates each line of code (often an intermediate code) at run time
• A compiler produces an executable file that will run on the target hardware machine without the compiler being installed  A run time interpreter will be required at run time
• Compilers tend to be large complex programs Interpreters are smaller simpler programs
• Interpreted programs can be amended and run without translating whole program Compiled programs have to be re-compiled after a change
• Compilers compile programs that will usually only run on the target platform (hardware/operating system)  Interpreters will interpret same program (or intermediate code) on different (some virtual) platforms

1. Commercial off-the-shelf (COTS) software: Organizations can purchase pre-developed software solutions from commercial vendors. These software products are typically ready-made and designed to fulfill common business needs. Examples include productivity software, customer relationship management (CRM) systems, and accounting software. COTS software can be licensed based on a one-time purchase or a subscription model.

2. Custom software development: Organizations may choose to develop custom software tailored to their specific requirements. This involves hiring software developers or outsourcing the development work to a third-party vendor. Custom software offers flexibility and can be designed to align with unique business processes and workflows. It allows organizations to have full control over the software's features and functionality.

3. Open-source software: Open-source software is developed collaboratively and made freely available to the public. Organizations can acquire open-source software without incurring licensing costs. They have the right to use, modify, and distribute the software as per the terms of the open-source license. Open-source software can be an economical option, and it allows organizations to benefit from community-driven development and ongoing improvements.

4. Software as a Service (SaaS): SaaS refers to software applications that are accessed and used over the internet. Organizations can acquire software on a subscription basis, where the software is hosted and maintained by the vendor. Users access the software through web browsers or dedicated client applications. SaaS eliminates the need for local software installation and offers scalability and accessibility from any location with an internet connection.

• Use of debugging utilities
• Use of test data
• Dry run / Desk checking

System analyst

Web designers

Network administrators

Database administrators

Programmers

Computer technicians