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IT topics explained

Learn the key ideas behind the devices, websites and services you use.

Computer hardware

Hardware means the physical parts of a computer. The CPU processes instructions, RAM holds data currently in use, and an SSD or hard drive stores files for later. The motherboard connects the components.

Example: when you open a document, the computer loads data from storage into RAM so the processor can work with it.

Explore the component guide →

Software and operating systems

Software is the set of programs and instructions a computer runs. An operating system, such as Windows, macOS or Linux, manages hardware and provides services for applications.

Example: a word processor is application software; the operating system manages saving its files and sending a document to a printer.

Watch the hardware and software video →

Networks and the internet

A network connects devices so they can exchange data. Ethernet uses a cable; Wi-Fi uses radio waves. A router forwards data between networks. The internet connects many networks around the world.

Example: your laptop connects to a router to request a web page from a server. DNS helps translate the site's domain name into an IP address.

Watch the networking video →

Online safety and cybersecurity

Protect your accounts with unique passwords and two-step verification. Install updates, keep backups and check links before opening them. Phishing messages pretend to be trustworthy to trick you into sharing information or downloading harmful files.

Try this: if a message asks you to sign in urgently, open the service's official website yourself instead of following the message's link.

Web development

HTML gives a web page its structure, CSS controls its appearance and JavaScript adds interaction. A responsive layout adapts to different screen sizes so a site works on phones and computers.

Try this: create a page with a heading, a paragraph and a link, then use CSS to change the colours and spacing.

Find web development resources →

See HTML and CSS working together

HTML gives the card its content and structure.

<article class="it-card">
  <h3>My IT project</h3>
  <p>I am learning HTML and CSS.</p>
  <a href="topics.html">Explore IT topics</a>
</article>

CSS gives the card spacing, a border and its colours.

.it-card {
  padding: 1.25rem;
  border: 1px solid #c7dfeb;
  border-radius: 0.75rem;
  background: #f4f9fc;
}
.it-card h3 { color: #175275; }

This is how those two pieces work together.

My IT project

I am learning HTML and CSS.

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IT revision cards

Try answering each question in your own words before opening the answer.

CPU

What does the processor do?

It carries out instructions and calculations, working with memory and other components.

RAM

What happens to RAM when power is off?

Its working data is normally lost. RAM is temporary memory, so save files to storage.

SSD

How is an SSD different from RAM?

An SSD stores files and applications persistently. RAM holds data for active tasks.

DNS

Why do websites use domain names?

Domain names are easier to remember. DNS helps translate a name into an IP address.

CSS

What controls a web page’s appearance?

CSS controls colours, fonts, spacing and layout. HTML provides the structure.

Router

What does a router connect?

It forwards traffic between networks. A home router usually connects your local network to the internet.

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