REST API/Considerations

All the calls are granular, meaning that each of the REST API calls operate on a single entity
Each REST API call is treated as a single transaction
In most cases, APIs have a direct one-to-one mapping with the UI
Data input and output can be in either in XML or JSON format
It is necessary to login to the platform before making a REST API call (and logout afterwards)
All REST API calls execute within the context of the User that is logged in. As with all UI actions, this means that any subsequent REST API calls (to access levels, data visibility, team membership, etc.), are governed by the Role Based Access Permissions granted to the User.
REST API calls are broadly categorized as Data API or Metadata API (excluding login/logout)
Data calls can span multiple objects, for example, the owner field in an object, or Lookups (foreign key relationships) to some other objects

The REST API implements the database CRUD model (Create, Read/Select, Update, Delete) using HTTP protocol requests(GET, POST, UPDATE and DELETE).

Field elements are optional in record updates. If a field is missing, existing data in that field is unaffected. If a field is present, but empty, any existing data in that field is deleted.