What are Generics in C#?

Generics is the implementation of parametric polymorphism. Using parametric polymorphism, a method or data type can be written generically so that it can deal equally well with objects of various types. It is a way to make a language more expressible, while still maintaining full static type-safety.

Why use generics?

There are mainly two reasons to use generics. These are:

• Performance – Collections that store objects use Boxing and Unboxing on data types. This uses a significant amount of overhead, which can give a performance hit. By using generics instead, this performance hit is removed.

• Type safety – There is no strong type information at compile time as to what is stored in the collection.