Deploy Webpart as Solution Package and Feature

To create a Webpart Solution Package and to Deploy it into sharepoint enviornment ...
1. You need to create an xml file called "manifest.xml" in webpart project.
2. Add a cab/setup project into webpart project .
3. Finally use Stsadm to add your solution to the sharepoint.

To activate/deploy the soution , you can go into sharepoint solution management in operations in Central Admin. OR can use Stsadm to deply the soution.

Details:
http://leedale.wordpress.com/?s=deploying+a+webpart

To Deploy a WebPart as a Feature ...

1. You need Feature.xml and Elements.xml.
2. Features are usually wraped in solution package.
3. So we need manifest.xml also.

Details :
http://www.sharepointnutsandbolts.com/2007/05/deploying-web-parts-as-feature.html

How to Creating a solution package to deploy Webpart feature:
Details :
http://www.sharepointnutsandbolts.com/2007/07/building-and-deploying-sharepoint.html