What Is Cyber Security? Key Concepts and Types of Threats

Cyber security is the set of practices that protect computers, servers, networks, mobile devices and data against unauthorised access, attacks and damage. The goal is to keep information confidential, ensure it isn’t altered and make sure it’s available when needed.

In this article we explain the basic concepts of cyber security, its sub-fields, the most common types of threats and the basic measures individuals and businesses can take.

The Foundation of Cyber Security: The CIA Triad

Principle	Meaning	Example measure
Confidentiality	Only authorised people can access information	Encryption, access permissions, multi-factor authentication
Integrity	Data isn’t changed without permission	Digital signatures, version control, change logs
Availability	Systems work when they’re needed	Backups, redundant infrastructure, DDoS protection

Sub-Fields of Cyber Security

• Network security: firewalls, intrusion detection and prevention systems (IDS/IPS), VPNs and network segmentation.
• Endpoint security: antivirus/EDR software on computers, phones and servers, and keeping them updated.
• Application security: secure coding, web application firewalls (WAF) and security testing.
• Cloud security: permission management in cloud accounts and preventing misconfigurations.
• Identity and access management: deciding who can access what; the principle of least privilege.
• Data security: encryption, data classification and data loss prevention.
• Incident response and business continuity: planning what to do during an attack and recovering from backups.

The Most Common Cyber Threats

Threat	How it works
Phishing	Fake emails, SMS or websites that trick users into giving away passwords or card details
Ransomware	Encrypting files and demanding a ransom to unlock them
Malware	Getting into systems with viruses, worms, trojans and spyware
DDoS attack	Flooding a server or network with requests until it can’t serve users
Brute force	Guessing passwords by trial and error
SQL injection and XSS	Exploiting flaws in web applications to access the database or run code in users’ browsers
Social engineering	Exploiting people’s trust instead of a technical flaw
Insider threats	Authorised people causing harm, intentionally or not

Basic Measures for Individuals

1. Use different, long passwords for every account; a password manager makes this easy.
2. Turn on multi-factor authentication (MFA) wherever possible.
3. Keep your operating system, browser and apps up to date.
4. Verify the sender before opening unexpected email attachments and links.
5. Back up important files regularly to a place separate from your main device.
6. Avoid sensitive transactions on public Wi-Fi networks.

Basic Measures for Businesses

• Asset inventory: know the systems and data you need to protect.
• Patch management: apply security updates on a regular schedule.
• Access control: give employees only the permissions their work requires, and make MFA mandatory on admin accounts.
• Backup strategy: the 3-2-1 rule: 3 copies, 2 different media, 1 copy off-site. Test restoring from backup regularly.
• Awareness training: most attacks target people; brief employees regularly.
• Regular testing: find weak points before attackers do with vulnerability scanning and penetration testing.
• Incident response plan: write down in advance who does what when an attack is detected.

For Server and Website Owners

• Use keys instead of passwords for SSH access and disable direct root login.
• Leave only the necessary ports open in the firewall.
• Use an SSL certificate on your website and keep your CMS and plugins up to date.
• Install tools that limit failed login attempts (e.g. Fail2Ban).
• Monitor logs regularly and watch for unusual traffic or logins.

Frequently Asked Questions

Are cyber security and information security the same thing?

They are closely related. Information security covers protecting all information, including paper documents. Cyber security focuses on digital systems, networks and data.

Is antivirus software enough?

No. Antivirus is an important layer, but without updates, strong passwords, MFA, backups and careful use it doesn’t provide enough protection on its own.

Are small businesses targeted too?

Yes. Attackers often scan for any vulnerable system with automated tools; small businesses can be easy targets because they take fewer precautions.

Where should I start for a career in cyber security?

Networking fundamentals, Linux and a scripting language (Python, Bash) are a good start. From there you can continue with security fundamentals and hands-on lab work.