Difference between System.Web.UI.WebControls.WebParts.WebPart and Microsoft.SharePoint.WebPartPages.WebPart?

Microsoft.SharePoint.WebPartPages.WebPart is provided in MOSS 2007 to provide backwards compatability with MOSS 2003 webparts.

 In MOSS 2007, it is recommended to use System.Web.UI.WebControls.WebParts.WebPart instead.

System.Web.UI.WebControls.WebParts.WebPart does not provides a feature to get or provide to to other webparts.

Client Object Model vs Server Object Model in SharePoint 2010

Client Object Model 

Client object model is a new feature available in SharePoint 2010. .Client object model provides a  way to do the programming for a SharePoint site using scripting language such as Java Script .

In  Client object model an xml request will be sent  and then server will return JSON which is changed to appropriate object model. 

Mainly 2 assemblies to be referred while working with the Client object model.

Microsoft.SharePoint.Client.dll

Microsoft.SharePoint.Client.Runtime.dll

Below is the code sample for a list object from SharePoint site using Client object model :

ClientContext context = new ClientContext("http://sp2010:2012");

 List list = context.Web.Lists.GetByTitle("Title");

context.Load(list);

context.ExecuteQuery();

So, what else a developer can do with Client object model. Client object model provide a way where you can access SharePoint data with scripting language such as Java Script.

You can write simple java script code to perform all those operation. You can use CAML query to access data from SharePoint site.

Using Client object model you can do below tasks:

Get list items, Add list items, Update list items and many more.

Client object model gives result in fast manner, but there is a limitation. The limitation is, we can not access Farm Object using Client object model.

For Client object model silverlight is also an option to program for a SharePoint site.

So if you want to access Farm object then use Server object model.

Server Object Model :

Server object model contains following classes : SPFarm, SPServer, SPSite, SPSiteCollection etc.

Below is the code Sample for Server Object Model:

This code is to get the list items from a SharePoint site:

          using (SPSite oSite = new SPSite(@"http://sp2010:33051"))

            {

                using (SPWeb oWeb = oSite.RootWeb)

                {

                    SPList oList = oWeb.Lists["List1"];  

                    Console.WriteLine("Items in: " + oList);

                    foreach (SPListItem oItem in oList.Items)

                    {

                        string firstname = oItem["Fname"].ToString();

                        Console.WriteLine(firstname);

                    }

                 }

            }

If you want more on Client object model or Server object model then please comment your query. Your comment will be highly appreciated.