Good security isn't just about the tools you own. It's about whether anyone is actually watching them. Once you accept that, the next question is what to do about it, and that's where it gets confusing, because the answer arrives wrapped in acronyms. EDR. XDR. MDR. Three letters that sound almost identical and seem to promise the same thing.
They don't. The difference isn't really technical. It's the difference between a smoke alarm and a fire brigade. One tells you there's a problem. The other actually turns up and deals with it. Understand where each of these three sits on that line and the jargon turns into a straightforward choice: how much of the work do you want to do yourself, and how much do you want done for you?
EDR, endpoint detection and response, watches your actual devices, the laptops, servers and phones where attacks usually play out. Rather than only blocking known threats, it looks for suspicious behaviour and raises the alarm, so something that slips past your other defences doesn't go unnoticed.
That's a real step up. But a smoke alarm only does one job: it makes a noise when something's wrong. Someone still has to hear it, work out how serious it is, and act. EDR is a very good alarm. It doesn't put anything out.
XDR, extended detection and response, widens the view. Instead of one alarm per room, it wires the whole building together, pulling signals from across your environment, email, network and cloud accounts, and connecting them. A fire rarely stays in one room, and an attack rarely shows up in one place; it spreads. XDR is what shows you the whole spread at once, rather than one alarm going off in isolation.
That makes detection sharper and cuts the noise, which matters when a busy setup can throw out thousands of alerts a day. But a better alarm system is still an alarm system. It tells you more, more clearly, and it still assumes someone capable is there to hear it and respond, at any hour. Without that person, XDR just means better alarms that nobody's answering.
MDR, managed detection and response, is different in kind, not just degree. You're not buying an alarm to monitor yourself. You're buying the response: a team using those detection tools on your behalf, listening around the clock, and turning up to deal with the fire when one starts.
Who's watching, and when? A staffed service, at all hours. How fast can someone act? They put it out themselves, isolating the device or shutting down the account, rather than phoning to tell you the alarm's going off. What's the plan if it takes hold? They have one, and they run it. MDR isn't the alarm. It's the people who come when it sounds.
Not your size or your budget first. It's whether you have the people, the time and the round-the-clock attention to answer the alarm yourself. A capable in-house team who can respond at 2am on a bank holiday will get real value from a sharper alarm like EDR or XDR. If you don't have that, and most businesses genuinely don't, a better alarm just means more noise with nobody to answer it. That's when what you're really buying is the response, and MDR is what that response is called.
The mistake worth avoiding is buying the alarm and assuming you've bought the fire brigade. A tool detects. Whether anything happens next is down to the people, and that has to be someone's actual job.
So when a provider talks to you in acronyms, cut through them with one question: which of these do you run for me, and which do I run myself? The answer tells you far more than the letters do.
If you're not sure which you've actually got, or whether the one you're paying for is being run the way you assumed, that's exactly what a free security review with entrustIT will show you: what's watching, who's responding, and where the gaps are.