What is cybersecurity?

What cybersecurity means

The US Cybersecurity and Infrastructure Security Agency (CISA) describes cybersecurity as the art of protecting networks, devices and data from unauthorized access or criminal use, and of ensuring the confidentiality, integrity and availability of information. Those three words, often shortened to the "CIA triad," are a useful way to think about any security problem:

• Confidentiality: only the right people can read the data. A leaked password database breaks it.
• Integrity: data isn't changed without permission. A fake bank-transfer instruction breaks it.
• Availability: systems work when you need them. Ransomware and DDoS attacks break it.

The field covers everything from a family's phones to hospitals, power grids and governments. This page focuses on what individuals can do, with a short look at who works in the field.

How big is the problem?

The FBI's Internet Crime Complaint Center (IC3) received 859,532 complaints in 2024, with reported losses of about $16.6 billion, a 33% rise from 2023 and the highest figure since IC3 started in 2000. Phishing and spoofing were the most reported crime type. People over 60 filed the most complaints and reported the largest losses. These are only crimes people reported, so the real totals are higher.

The main threats individuals face

For the big attacks on companies and governments, see our history of major cyber attacks.

The basics: what CISA and the NCSC recommend

Government security agencies give remarkably similar advice. CISA's public awareness guidance lists four steps for everyone: recognize and report phishing, create strong passwords, turn on multifactor authentication and use a password manager, and keep software updated. The UK National Cyber Security Centre's Cyber Aware campaign lists six tips that overlap closely.

1. Use strong, unique passwords Both agencies recommend strong passwords and a password manager to create and remember them. The NCSC suggests building passwords from three random words, and says to start with a strong email password you use nowhere else, since criminals can use your email to reach your other accounts. See password managers.
2. Turn on multi-factor authentication Both agencies put this near the top. An authenticator app, a passkey or a hardware security key is stronger than a text message, but any second factor is better than none.
3. Update your software Turn on automatic updates for your phone, computer, browser and apps. Most attacks use flaws that already have a fix.
4. Recognize and report phishing Be wary of urgency, unexpected attachments and requests for codes or payment. Check by contacting the organization through a channel you already trust.
5. Back up your data The NCSC lists backing up important data, such as photos and documents, to an external drive or cloud storage. A recent backup turns ransomware or a lost phone from a disaster into an inconvenience.

Next steps if you want to go further

• Use a privacy-focused browser and block trackers. See private browsers.
• Move private conversations to end-to-end encrypted apps. See encrypted messaging apps.
• Check whether your email appears in known breaches with a service such as Have I Been Pwned.
• Reduce what data brokers hold about you. See data broker removal.
• Learn the vocabulary in our security glossary.

Who works in cybersecurity

Cybersecurity is done by many kinds of organizations, public and private. We describe them by type. We don't rank companies.

• Security vendors make products such as antivirus and endpoint protection, firewalls, identity and login tools, email filtering and cloud security. They range from large public companies to small start-ups.
• Incident-response and forensics firms are hired after a breach to find out what happened, remove the attacker and help with recovery. Their public reports are a major source of information about how attacks work.
• Managed security providers run monitoring and response for organizations that don't have their own security team.
• National agencies and CERTs. Computer emergency response teams, also called CSIRTs, coordinate responses to incidents. Examples are CISA in the US, the NCSC in the UK and CERT-EU for EU institutions. The CERT Division at Carnegie Mellon University's Software Engineering Institute grew out of the CERT Coordination Center, a small incident-response group whose first director led it from 1988. FIRST, the Forum of Incident Response and Security Teams, links response teams worldwide.
• Academic and research centers study attacks, cryptography and policy. The Citizen Lab at the University of Toronto, for instance, is known for investigating commercial spyware used against civil society.
• Standards bodies such as NIST publish frameworks and guidance. NIST's Cybersecurity Framework 2.0 organizes security work into six functions: govern, identify, protect, detect, respond and recover.
• Independent researchers and nonprofits find and report flaws, often through bug bounty programs, and campaign on digital rights. Some well-known hacker groups do this kind of work in public. See our profile of the Chaos Computer Club.

If you are curious about the people behind attacks, see what is a hacker and our hackers overview.