All .NET compilers produce metadata about the types defined 
in the modules they produce. This metadata is packaged 
along with the module (modules in turn are packaged 
together in assemblies), and can be accessed by a mechanism 
called reflection.

The System.Reflection namespace contains classes that can 
be used to interrogate the types for a module/assembly. 

Using reflection to access .NET metadata is very similar to 
using ITypeLib/ITypeInfo to access type library data in 
COM, and it is used for similar purposes - e.g. determining 
data type sizes for marshaling data across 
context/process/machine boundaries.

Reflection can also be used to dynamically invoke methods ( 
System.Type.InvokeMember ) ,  or even create types 
dynamically at run-timeystem.Reflection.Emit.TypeBuilder). 

reflection is a collection of metadata and combination of
manifest.it can also be used to dynamically invoked method.

Reflection is a concept of reverse engineering. The process in order to read and access mechanism of control or assembly is called reflection. It can be performed by using System.reflection namespace in .net

Top two answers can be provide after it.

Thanks.