Installation, Deployment, Activation of Features
I get plenty of questions on how to add, deploy or activate a SharePoint Solution.
Solution
A SharePoint solution is a *.wsp file (which is a cab file) which contains at least one feature.
Feature
A feature adds new functionality to your SharePoint farm. It can be wrapped inside a solution file, or be deployed by adding files to your SharePoint servers.
Installing a Solution
To install a solution to your SharePoint farm, copy the wsp file to one of your SharePoint servers, and run “stsadm -o addsolution -filename yoursolution.