"General user", "End user" or "Normal user", which one is better?

How about simply "User" versus "Programmer"?

It is enough to make the right distinction and you don't have to call anybody "common" or anything.

If you are describing the system it would be perfectly correct to call this group 'end users', however, I agree with Ishmaeel in the case that you want to give the group a visible name then simply 'users' would be more appropriate.

Paul, I work in the software industry and End User is a widely accepted terminology. It describes the people who will actually be using your software to meet their ends.

It's fine if you want to use "User" but "End User" is perfectly acceptable.

Sometimes it's best to name the users based on the role they are performing. Programmers are users of the system too, but they are programming it. The other users are operating those programs, but "operator" sounds wrong to me. In this case if there is no defining characteristic for the non-programmer users then simply calling them "users" is probably best.