Performance overhead for properties in .NET

Question

I read somewhere that having public properties is preferable to having public members in a class.

1. Is this only because of abstaraction and modularity? Are

Answer 1

It is mostly for purposes of abstraction (you can later add validation without breaking existing code, or requiring recompilation).

Even when using auto-properties, there is still a backing field generated by the compiler, and will perform as such.