EDR vs traditional antivirus: what is the difference?

This page is for owners who see antivirus and EDR on IT quotes and want to know whether the more expensive option is worth it. It explains what each tool sees, what the word response means in practice, and how a very small business can make a sensible choice.

The short version

Traditional antivirus mainly looks for known bad files and patterns. EDR stands for endpoint detection and response. It watches what happens on a computer or laptop, looks for behaviour that suggests an attack, and gives someone the information and tools to contain it. An endpoint is simply a device that connects to your business: usually a Windows PC, Mac or server.

The two are not always separate products. Modern EDR often includes the anti-malware protection people still call antivirus. The important difference is not the label on a quote. It is whether the product can spot suspicious activity that does not match an old virus signature, and whether somebody will investigate and act when it raises an alert.

This matters because a device is often the next target after an email account is compromised. MFA reduces the chance of that first sign-in being stolen; see our explanation of multi-factor authentication. EDR then helps limit what happens if a malicious file, stolen session or unpatched weakness gets past the first line of defence.

What traditional antivirus does well

Antivirus is not useless or old-fashioned. It still blocks a great deal of everyday malware. It checks files, downloads and programs against known signatures and reputation information. If a piece of ransomware has been seen before, or a website is known to deliver malware, a decent product may stop it before a user notices anything.

For a low-risk, tightly managed device, built-in protection with automatic updates is a meaningful baseline. It is far better than running without any protection, which is still more common than it should be on unmanaged home PCs and occasional-use machines.

The limitation is that signatures are strongest when the threat is already known. Criminals change filenames, alter code, use legitimate remote-management tools, or persuade a user to run something themselves. A program can look ordinary in isolation while its actions are anything but ordinary.

• Good at: recognised malware, unsafe downloads and common threats.
• Less good at: new variants, misuse of legitimate tools and an attacker using valid credentials.
• Still needed: patching, backups, access control and staff who can spot a suspicious email.

What EDR adds

EDR records and evaluates behaviour on the device. It can notice, for example, a document launching a script, that script trying to disable security software, then a rapid burst of file changes across a shared drive. Each action might look harmless on its own. Together, they look much more like ransomware preparation than normal work.

It also keeps a trail. That helps answer useful questions after an alert: which device was affected, which account was used, what process started it, whether it reached a file share, and whether another machine shows the same signs. Without that visibility, an owner may be left choosing between hoping the warning was harmless and rebuilding everything.

EDR is especially useful against attacks that rely on behaviour rather than an obvious virus. Examples include a criminal using a stolen remote desktop login, running built-in administration commands, or attempting to move from one computer to another. It does not make these attacks impossible, but it gives you more chance to catch them early.

For the wider context, read our explanation of how ransomware reaches UK small businesses. It shows why an alert on one laptop should not be ignored just because the screen still looks normal.

What response actually buys you

The response part means the ability to act quickly. At the simplest level, the security tool can block a process or quarantine a file. In a managed setup, it can also isolate a device from the network while leaving it connected to the security service, stop a malicious process, collect evidence and guide the next steps.

Isolation is valuable. If a laptop starts encrypting shared files, taking it off the network may prevent the damage spreading to a server or other machines. A technician can then check what happened before putting it back. That is very different from waiting until staff report that files will not open.

Tools still need people. A busy owner cannot realistically inspect every warning at 9pm and decide whether it is a false positive. Ask who watches the alerts, what hours they cover, what happens if a device must be isolated, and whether the service includes help with recovery. Those questions belong in your IT support SLA discussion as much as in a cyber quote.

Does a very small business need EDR?

Not every one-person business needs the most involved managed EDR service from day one. If you have one or two well-maintained devices, strong MFA, automatic updates, a separate backup and no sensitive customer data beyond ordinary office records, good built-in protection may be a reasonable starting point. It still needs checking, not merely assumed.

The case for EDR gets stronger when you have several staff, remote workers, shared files, a server, access to customer data, payment information, or a contract that asks for evidence of security controls. It is also worth considering if losing access to your systems for a day would stop you trading. The cost should be weighed against the disruption, not just against a cheap antivirus licence.

Do not buy EDR and then leave the basics undone. Use supported software, apply updates promptly, remove old accounts, limit administrator rights and test your backups. Our business data backup guide explains why a backup you have not restored is only an assumption.

What to do next

Make a list of every business device and find out what protection is actually installed, whether it is monitored and who receives alerts. Then decide how much response you need based on your size, data and tolerance for downtime. TSS can review the setup in a free, no-obligation chat and give you a straight answer, including when standard protection is enough for now.