Grade 11 Computer Applications Technology Study Guide

Every time a learner at a school in Polokwane swipes a card in the tuck shop, or a parent in Khayelitsha buys airtime for R29 using a banking app, a computer system is quietly turning raw facts into useful information. Computer Applications Technology (CAT) is the Grade 11 subject that teaches you how these systems work and, more importantly, how to use them to solve real problems with documents, spreadsheets, databases and web pages. This chapter is your map of the whole year. It explains how the subject is organised, the big ideas you will keep returning to, and the foundational computing concepts that every later chapter assumes you already understand.

1.1 What CAT is and how the year is organised

CAT is a practical, skills-focused subject. You are not learning to build computers or to program them in a high-level language; you are learning to be a confident, ethical and productive end user of standard software. The CAPS curriculum groups the content into six knowledge strands: Systems Technologies, Hardware and Software, Social Implications, Network and Internet Technologies, Information Management, and Solution Development. The first five give you the theory of how computing works and how it affects society; the sixth is where you apply everything in Microsoft Word, a spreadsheet program, a database program and basic HTML.

In practice the subject is assessed through both theory and practical work. A Practical Assessment Task (PAT) runs across the year, in which you research a real problem, process the data and present a solution. Knowing this from day one helps you see why the early theory chapters matter: they are the vocabulary and reasoning you will use in the practical work.

1.2 Data, information and the information processing cycle

The single most important idea in CAT is the difference between data and information. Data are raw, unprocessed facts that on their own have little meaning, such as the numbers 18, 23 and 21. Information is data that has been processed so that it becomes meaningful and useful, such as the statement that the average daily temperature in Bloemfontein last week was 21 degrees Celsius. When information is interpreted and applied to make decisions, it becomes knowledge.

A computer turns data into information using the information processing cycle, often shortened to IPO: Input, Processing, Output, supported by Storage and Communication. You give the system data (input), the system manipulates that data according to instructions (processing), and it produces a usable result (output). Storage keeps data for later, and communication moves it between devices. You will meet the physical devices that do each step in Chapter 2 and the software that controls them in Chapter 3; here you only need the conceptual cycle.

1.3 The parts of a computer system: hardware, software, people, data and procedures

A complete computer system is more than a machine. It has five interacting elements that you should be able to name and explain:

• Hardware — the physical, touchable parts such as the keyboard, screen and storage drive.
• Software — the sets of instructions that tell the hardware what to do, divided into system software and application software.
• Data and information — the facts that are entered and the meaningful results that come out.
• People (users) — the human beings who operate the system; in CAT the focus is on the end user.
• Procedures — the rules and steps people follow, such as how to back up files or log in safely.

This chapter keeps these at an overview level. The detail of each hardware device belongs to Chapter 2, and the distinction between system and application software is developed fully in Chapter 3.

1.4 Units used to measure data

To work with files and storage you must understand how digital data is measured. Computers store everything as bits (a single 0 or 1). Eight bits form one byte, which is roughly one character. Larger amounts are measured in kilobytes, megabytes, gigabytes and terabytes. The standard relationship used in CAT treats each step as a factor of about a thousand. We can write the size of a file as a product of bytes:

Knowing these units lets you judge, for example, whether a 4 GB flash drive can hold a 2,5 GB video, or how many R-priced data bundles you would need to download a large file.

1.5 Types of computers and ICTs in everyday South African life

You should be able to compare the common categories of computers by size, power and use:

• Servers — powerful computers that provide services to many users, for example the server that runs a bank such as Capitec.
• Desktop and laptop computers — general-purpose machines used in offices, labs and homes.
• Mobile devices — smartphones and tablets, the most common computing devices in South Africa.
• Embedded computers — tiny computers built into appliances such as a microwave or a smart electricity meter.

The phrase ICT (Information and Communication Technology) covers all the technologies that handle information and communication together. A learner using a free Wi-Fi hotspot at a public library in Durban to research a project is using ICTs to bridge the gap between having a question and having an answer. Throughout the year you will weigh both the benefits of these technologies and their social costs, a theme developed in Chapters 10 and 11. For now, your goal is simply to speak the language of computing accurately, because every chapter that follows builds on the vocabulary introduced here.