What exactly is an Assembly in C# or .NET?

Question

Could you please explain what is an Assembly in C# or .NET?

1. Where does it begin and where does it end?
2. What important information should I know about

Answer 1

The answer is in order for immediate-grasping.

Put simply, it is the compiled project involving your classes and additional files, if there are. That is, each project in a solution is assembly.

Or more techinally,

An assembly is where a type is stored in the flesystem. Assemblies are a mechanism for deploying code. For example, the System.Data.dll assembly contains types for managing data. To use types in other assemblies, they must be referenced. - Source

How do we know it? If you glance at properties of a project under the solution you can see the following images.

When you compile the project, it turns out to DLL or EXE.