Understanding C# Features (8) Covariance and Contravariance

[LINQ via C#] - [C# Features] In covariance/contravariance, variance is the capability to replace a type with a less-derived type or a more-derived type in a context. C# 4.0 and CLR 4 introduced covariance and contravariance for generics. Is-a relationship for inheritance Since covariance and contra