Visual Studio uses partial classes to separate auto-generated code from user-generated code. Its as simple as that m8.

The :Form part just means use a regular form as described by the .net framework. You can use 3rd party tools like DevExpress or KryptonForms to use other types of form, and as such, the :Form will be replaced with :KryptonForm or w/e.
jayfella Reviewed by jayfella on . [c#] variables, ifs, simple math and drawing objects Here is a little tutorial explains how to declare and use strings and integers, how to perform a basic integrity check and how to make use of these values by using an object. It also shows how to create these objects without using the Design view of Visual Studio. The code has been commented to make it easier to read, and is fully functional. You can simply copy-paste its entirety into a new project. using System; using System.Collections.Generic; using System.ComponentModel; using Rating: 5