Explanation for "double" in data types . Detailed manner?

Question

Confusion on getting to this "double" in data types.

Answer 1

double is a data type that is used to store values with a decimal part. For example, you use an "int" to store the value 5. But you can't store 5.56 in an "int". So we use double to store 5.56, or a similar number with a decimal part. float is also like double, but it is of less precision.

Answer 2

Double is similar to real numbers from a school.