What is difference between MemoryCache vs ObjectCache in .net 4.0?

Question

What is difference between .NET framework 4.0 MemoryCache vs ObjectCache? Where to use which object?

Answer 1

ObjectCache is an abstract class, you can't 'use' it per se. As Dash says in his comment, it's designed to show how a cache should be built and what operations it supports. MemoryCacheis an implementation of ObjectCache and from your question is likely what you should use. However, because ObjectCache is abstract, you could just as easily write your own FileCache inheriting from ObjectCache and it would be perfectly valid.