Essentially GET creates a query string which makes it possible to invoke a request directly from the URL on a browser. Web servers actually cache the results of GET requests for performance reasons.
POST actually sends the data directly to the server and the result is never cached.

This means that GET will be cached by browsers like IE rather than being called every time, whereas POST (when data is included) will not be cached.In Repliconnect API, GET commands cannot be used instead of POST ,because, it has been noticed that the API runs into a variety of issues with GET including mainly length of query string issues.