what is diifference between webpart and visual webpart?

In Web part, everything has to done through code for UI as well as logic. It does not provide visual UI effect. Hence it affects the productivity.

Visual web part is a web part which contains the reference of user control in which we can place controls from designer and have separate code file to add business logic inside it. It improves the productivity to design the complex UI.

 

Web part can be deployed as a sandbox solution hence it will not impact the whole farm if any issue with simple web part code.

In SharePoint 2010, Visual web part cannot be deployed as a sandbox solution. It can be deployed as a farm solution.You can use Visual studio 2010 SharePoint power tools extension to deploy visual web part as a sandbox solution. Power tool generate the complied code with user control as a part of assemblyFew web controls are not supported in sandbox solution as visual web part gives an error occasionally. 

 

Web part can be extended by inheriting from the WebPart class. We cab reuse the web part functionality. Visual web parts cannot be extended.

 

 I hope this is helpful!

Ben Martin