What means "I" in c#?

Question

Hello everyone I had interview today then interviewer asked me:- What means I commonly used in IEnumerable ICollection IList in c#? I do not understand.

Shakti Singh Dulawat · Answer

So as per my view you should answer I belong to Interfaces in c#  IEnumerable ICollection and IList are interfaces in the .NET Framework.

Vivek Kumar · Answer

Yes I belong to interface.