I\'m in need of some clarification. I\'ve been reading about REST, and building RESTful applications. According to wikipedia, REST itself is defined to be Representation
You have to manage client session on the client side. This means that you have to send authentication data with every request, and you probably, but not necessary have an in-memory cache on the server, which pairs auth data to user information like identity, permissions, etc...
This REST statelessness constraint is very important. Without applying this constraint, your server side application won't scale well, because maintaining every single client session will be its Achilles' heel.