What is difference between listdata.svc and clients.svc in SharePoint? Both are webservices and can be used to fetch list items..
While To get the data from Sharepoint list via REST we use listData.svc.
For more details:
ListData.svc - only if list data is needed
Client.svc - List data and oData operation
The "_api" is friendly name, since it's easier to read. The old SharePoint 2010
/_vti_bin/ListData.svc is still there in SharePoint 2013, and is handy if only List data is needed.
In SP2010 -
In SP2013 is replaced