In C#, what is the difference between public, private, protected, and having no access modifier?

Question

All my college years I have been using public, and would like to know the difference between public, private, and protected

Answer 1

Yet another visual approach of the current access modifier (C# 7.2). Hopefully the schema helps to remember it easier
_{(click the image for interactive view.)}

Outside Inside

If you struggle to remember the two-worded access modifiers, remember outside-inside.

• private protected: private outside (the same assembly) protected inside (same assembly)
• protected internal: protected outside (the same assembly) internal inside (same assembly)