What's that line over a repeating decimal called? (Ex- 3.33 The line would go on top of the second 3)

Question

And also, what's the difference between that line going on top of the second number and it going on top of both numbers? (Ex 1- 3.33 The line would go on top of the second,3. Ex 2- 3.33 The line would go on top of both,33.)

Answer 1

I will underline instead of overlining.

0.3 = 0.3333333333333333
It is clear that

If both numbers are the same, there is no difference. Otherwise, there is a difference.

3.3 = 3.333333333...
3.34 = 3.3434343434343434...

Surely your text has explanations and examples of this notation...

Answer 2

Thanks! :)