Sharepoint 2010 Client Object Model

1. Why do we need Client Object Model ? /  Why Client Object Model evolved ?
    
        Microsoft was constantly getting request from customers for more webservices. to make it easier to get data from outside of sharepoint (for example : to show sharepoint data on your desktop, by consuming a webservices), So there are two options: 1) Request microsoft to produce more web serivices or 2) Create your own custom web services, Instead creating more and more web services over and over agin in each release,  Microsoft  came up with a different approach , they created someting called 'Client Object Model'.
 
2.Client Object Model comes in three flavours:

a. .NET web services
b. ECMAScript(javascript)
c. Silverlight

      

3.Where SP Client Object Model can be used to get data :

 a.Site Collections and Sites
 b.Lists,List Items,Views, and List Schemas
 c.Files and Folders
 d.Web,List, and List Item Propert bags
 e.Web parts
 f. Security
 g.Content Types
 h.Site Templates and Site Collection Operation


SharePoint 2010 allows using its Object model to run against a server running SharePoint. For clients (not running SharePoint in the box), the simplest way to communicate with SharePoint server is web services. SharePoint Client Object Model (OM) can be run on client PC (where SharePoint is not installed) to communicate with SharePoint server. So whereas SharePoint (Server) Object Model runs in a SharePoint server and can manipulate SharePoint objects, client OM can run in client PC and communicate with SharePoint server remotely.



Video : http://msdn.microsoft.com/en-us/SP2010DevTrainingCourse_OverviewoftheClientObjectModel