Depending on your perspective, Live Services can take on different meaning. To the end-user, Live Services are the Windows Live applications (SkyDrive, Spaces, Hotmail,etc). A relative newcomer to the Windows Live family is Live Mesh, we'll talk more on that later.
To the developer, Live Services are the APIs exposed by Microsoft for building applications that leverage and/or enhance the Windows Live applications on behalf of the user. Technically there are two sets of API for Windows Live development: the Live Services SDK, and the Live Framework SDK. The difference between the two?