An asset is any system, service, device, account, application, data set, or other resource that has value to an organization and therefore needs protection. In cyber security, assets are the things defenders must identify before they can assess risk, set priorities, or choose controls.
Assets matter because attacks usually target them indirectly: a public web server, a cloud workload, a supplier connection, or a privileged account can all be entry points or high-value targets. If defenders do not know which assets are critical, they may protect the wrong systems or miss a weak dependency. Good asset management helps with patching, access control, monitoring, backup planning, and incident response. In practice, security teams map assets to business services, then decide which ones need stronger safeguards based on impact if they fail, are stolen, or are misused.