Endpoint security is the practice of protecting the devices, or "endpoints," that connect to a network, such as laptops, desktops, phones, tablets, servers, and Internet of Things (IoT) devices, from cyber threats. Because each connected device is a potential entry point for an attacker, endpoint security aims to secure every one of them, and to control how they interact with the network and its data. It combines protection installed on the devices themselves with network-level controls that govern their access.

Why is endpoint security important?

Every device that touches a network expands its attack surface. The more endpoints, the more ways in, and the trend toward mobile working, personal devices, and IoT has multiplied endpoints dramatically. A single compromised laptop or an insecure IoT sensor can become the foothold from which an attacker reaches deeper into an organisation's systems and data. Since data is usually an organisation's most valuable asset, and much of it flows through or is reachable from endpoints, securing those endpoints is a foundational part of any security strategy.

How does endpoint security work?

Traditional endpoint security places protective software on each device, an Endpoint Protection Platform (EPP), which guards against malware and blocks known threats. Increasingly, much of the protection also happens in the network or the cloud rather than solely on the device: traffic is inspected, policies are enforced at the point of connection, and threats are detected by watching behaviour across many endpoints at once. Modern approaches focus on protecting the interactions between users, applications, and data, rather than only hardening each device in isolation.

Types of endpoint security controls

Organisations combine several complementary controls. Network Access Control (NAC) limits which devices may connect to the network or to specific parts of it. Data Loss Prevention (DLP) guards against sensitive data being exfiltrated. URL filtering restricts which websites endpoints can reach, since malicious sites are a common infection route. Data classification identifies the most sensitive information so it can be protected more tightly. Sandboxing runs untrusted code or sessions in an isolated environment so it cannot touch real systems. Encryption protects data on the device and in transit. Together these controls address different stages of how a threat might enter or spread.

Endpoint security and unmanaged devices

A particular challenge arises when an organisation does not own or control the endpoints, for example a network open to visitors' or members' personal devices. Software cannot be mandated on devices the organisation does not manage, so protection shifts toward the network layer: controlling access by identity, isolating untrusted devices onto restricted segments, and monitoring behaviour to detect compromise. In these environments, the network itself becomes the primary line of defence, containing an untrusted or compromised device rather than relying on protection installed on it.

The role of AI and analytics

As threats grow more sophisticated, endpoint security increasingly uses artificial intelligence and behavioural analytics. By analysing patterns of user and device behaviour, these systems can flag anomalies, an account behaving unusually, a device communicating in unexpected ways, that signal a compromise or an insider threat. Ranking anomalies by risk lets security teams focus their limited attention on the threats that matter most, shifting from purely reactive defence toward predicting and preventing attacks.