Aleph null is the cardinal number that is given to an infinite set of the smallest size, like the natural numbers. It is the smallest "infinite cardinal number". The cardinality of the real numbers, while still infinite, is greater than aleph null.
Is Aleph Null a natural number?
It can't be some number in the naturals, because there'll always be 1 plus that number after it. Instead, there is a unique name for this amount: 'aleph-null' (ℵ0). Aleph is the first letter of the Hebrew alphabet, and aleph-null is the first smallest infinity. It's how many natural numbers there are.
What is the use of Aleph Null?
The size of infinite sets is indicated by the cardinal numbers symbolized by the Hebrew letter aleph (alef>) with subscript. Aleph-null symbolizes the cardinality of any set that can be matched with the integers.
