microsoft .net framework

It's basically these programming files that enable certain programs that need it to run. Kind of like those old visual basic files you needed to have to run those old VB programs in the past. I install the framework because you'll run into a program that needs it eventually.

I really do not understand what ms .net framework is. As you know this is found on the windows update site as optional. Do I need this or is this something that is helpful?

I tried looking this up online, but I sure could use your help in plain simple english as to what this is.