MEF Meaning:

MEF or the Managed Extensibility Framework refers to a digital library for the formation of extensible technical applications. Using it, software developers and programmers can utilize the available extensions without any coding or configuration. You can even use MEF across applications during their development stage. You can reuse it for multiple times.

Benefits of MEF:

• MEF helps in arranging smaller components 
• An MEF component can be easily categorized as imports (dependencies) or exports (capabilities).
• MEF helps an app function without any codes or config files.
• You can analyze all parts using metadata.

Location of MEF

MEF is a constituent part of the .NET framework. Everytime you use .NET, you have to use MEF as well. MEF works in sync with .NET client as well as ASP.NET and in other technology as well. 

MEF Composition

MEF composition basically includes a composition container having all available parts assembled together. It is responsible for performing various computing operations. A part represents any object through which any value can be exported or imported.   

Imports and Exports of MEF:

Imports and exports are just a behavioral pattern of how MEF parts operate within the .NET framework. When the component delineates the necessity of assigning a value to a particular object, it is called Imports. While export determines whether the same is available or not. Each import has to be matched with their corresponding export in the MEF.