Question

what is the basic concept of infinity

Answer 1

Infinity (symbol: ∞) is a concept describing something without any bound or larger than any natural number. ... In mathematics, "infinity" is often treated as a number (i.e., it counts or measures things: "an infinite number of terms") but it is not the same sort of number as either a natural or a real number.

Answer 2

the basic concept of infinity is not countable