eli5 how does the sum of infinite terms turns to be a finite value

Question

does this apply only for terms that are less than 1 eg 1 + 1/2 + 1/4…. or does this apply to all ap/gp. I remember studying this, but it’s been so long I remember only the gist.

In: 248

Answer 1

1 + 1/2 + 1/4 ….
You can create this sum with a piece of paper which you cut in half at every step. This may help you visualize that you end up with 2