Last updated: 7 November 2026
EDR watches devices, ITDR watches identities and sign-ins, SIEM collects logs from everything, XDR links several of those together, a SOC is the team of analysts who investigate, and MDR is a service that bundles the tools and the analysts. Small businesses usually buy managed detection and response (MDR) rather than running the pieces themselves.
The six terms side by side
| Term | Stands for | What it covers | Plain-English job |
|---|---|---|---|
| EDR | Endpoint detection and response | Laptops, desktops, servers | Spots and stops attacks on a device |
| ITDR | Identity threat detection and response | Microsoft 365 and Entra sign-ins | Stops account takeover |
| SIEM | Security information and event management | Logs from everything | Collects, correlates and keeps evidence |
| XDR | Extended detection and response | Devices, email, identity and cloud together | Joins several tools into one view |
| SOC | Security operations centre | People and process | Analysts investigating alerts, ideally 24/7 |
| MDR | Managed detection and response | Tools plus a SOC, as a service | Someone else watches and responds for you |
How they fit together
Which does a small business actually need?
Every business
EDR on every device and identity protection (MFA, Conditional Access) for Microsoft 365.
Most businesses
Someone watching the alerts out of hours, which is MDR rather than a tool you manage yourself.
Some businesses
SIEM-style log retention when contracts, insurers or regulators require evidence.
Anyone on Microsoft 365
ITDR, because account takeover is the most common way in.
Read the individual answers: What is EDR?, What is ITDR? and What is SIEM?
How ABCOM helps
ABCOM’s managed IT plans include EDR on every device with round-the-clock monitoring by a security operations centre, plus Microsoft 365 hardening and identity protection. We explain what you have in plain English, without acronym soup.
Quick answers
What is the difference between MDR and EDR?
EDR is the software on the device. MDR is the service: EDR plus the analysts who monitor alerts, investigate and respond for you.
What is the difference between a SIEM and a SOC?
A SIEM is the technology that gathers and correlates logs. A SOC is the team of people who act on what it finds.
Is XDR better than EDR?
XDR extends EDR by joining signals from email, identity and cloud. It can give a fuller picture, but for a small business the quality of monitoring matters more than the label.
We will explain exactly what protects your business today and what, if anything, is missing.
Related answers and guides
- What is SIEM?
- What is EDR?
- What is ITDR?
- What is user awareness training?
- Managed IT services
- All ABCOM FAQs
Sources and further reading
Related questions
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