Two is a whole number that's greater than one, but less than three. If you found one fuzzy mitten and then your friend gave you another one, you would have two mittens — perfect for your two hands.
In a deck of cards, there are four twos — one in each suit. In most games, the two is considered the lowest card. Two can also be used as an adjective to describe anything that numbers one more than one. In cards, if you have a pair of twos, you have two twos. This spelling of two always refers to a number and shouldn't be confused with the homonyms "to" or "too."