Rails, oauth vs oauth2

I want to know the difference between oauth and oauth2 g开发者_如何学JAVAems available in ruby and which one can be used to connect with various sites like facebook, twitter, salesforce etc (There are many plug-ins available for this but can we create a single APIs for connecting all oauth provider).

~N a R e N

---

These two gems differ by the version of OAuth standard they implement, respectively 1 and 2.

The choice depends on the OAuth providers you want to work with and what versions they support. For example, Facebook supports only OAuth 2, but some older systems might support OAuth 1 only.