Question

Is infinity a natural number,whole number, decimal, integer?
What is exactly infinity?

Answer 1

Infinity is not a number which fits any of the classifications. It cannot be reached by counting as it is "countless". You can't set it equal to any finite number as you can always add 1 to a finite number to obtain a higher number (and infinity is greater than any finite number). It can be used only in limits, in the sense that it is a number that can be approached but never equalled. So while it is correct to say limit of 1/ x as x approaches infinity = 0, we can't say 1/infinity = 0. What this means is that x becomes larger and larger, 1/x becomes smaller and smaller, until ultimately as x approaches infinity, 1/x approaches zero.
So think of infinity as number being approached but never actually equalled. (None of us have experienced what is infinity)