Partial classes and partial methods are two programming language features of .NET programming languages that make it possible for developers to extend and enhance auto-generated code.
Partial methods are methods defined in a partial class that are (optionally) divided across two files. With partial methods one file contains the method signature – the method name, its return type, and its input parameters – while the body is (optionally) defined in a separate file. If the partial method’s body is not defined then the compiler automatically removes the partial method signature and all calls to the method at compile-time. Compare with partial classes.