What does E' (Expression Prime) mean?

Question

So, I'm studying Compiler Construction and stucked in this grammar

E->TE' E->+TE' and so on.... My question is What does the E' means actually ?

Answer 1

The ' does not have any inherent meaning - it's just part of the name. That is E' is simply a rule named E' .

The usual reason you'd name the rule E' instead of just picking a new letter like F would be to express that E and E' are related somehow.