What is the "module" keyword in C# .NET?

Question

I am learning C# and came across the keyword module. I would like to know what this module keyword in C# is and how it is useful. For example, consider the below code:

[module: Test]
public class TestAttribute : Attribute
{
}

Answer 1

In your example module is a way to specify the attribute usage, like this:

[module: CLSCompliant(true)]
int Method1() { return 0; }

It is also called attribute target:

The target of an attribute is the entity which the attribute applies to. For example, an attribute may apply to a class, a particular method, or an entire assembly. By default, an attribute applies to the element that follows it.

For the full list of C# attribute parameters check the official documentation.