APIs in SharePoint 2010

Hi

   I want to know number of APIs in SharePoint. I have heard that there are 163 APIs in SharePoint. Is it so? I know only

             1) Server Object Model API

             2) Client Object Model API

             3) Javascript Client Object Model API

             4) Ecmascript API

             5) REST API

        If it is 163 API, please provide me book/site which helps to know about this API. Thanks in advance.