Which of the following best describes the set of real numbers?

Only positive integers and zero

Only fractions and their opposites

All rational and irrational numbers

Only numbers that can be written as terminating decimals

The two main subsets that together form the entire real number system are:

Rational and irrational numbers

It is only useful for abstract mathematical theories.

It helps in solving complex, real-world problems.

It is a prerequisite for learning basic arithmetic.

It primarily deals with counting objects.