An endpoint is any device connected to a network that processes data — laptops, desktops, smartphones, tablets, but also IoT devices and servers. Endpoints are the most frequent attack targets because they form the interface between people and IT infrastructure.
Securing endpoints involves encryption (full-disk encryption), patch management, endpoint protection software, device configuration, and access control. ISO 27001 Annex A dedicates several controls to endpoints (A.8.1, A.8.5). Mobile endpoints require additional measures such as remote wipe, MDM profiles, and secure containers for corporate data.