LDAP and Active Directory are protocols used in identity management but serve different purposes. LDAP is a vendor-neutral protocol for accessing and managing directory information over a network, while Active Directory is Microsoft's identity solution for managing user identities and resources on a Windows network. Both can be used together or independently depending on the organization's needs. LDAP is preferred when there's a need for a lightweight solution to access directory information without being tied to a specific vendor, whereas Active Directory is widely used in enterprises, especially those using Microsoft products and services.