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

you have a 2L bottle

you pour 1L of water – 1 to go

then half of that, 0,5L – 0,5 to go

then half of that, 0,25 – 0,25 to go

when you repeat, you will always have a bit more to go