Rational numbers are numbers which can be expressed as a fraction and also as positive numbers, negative numbers and zero. It can be written as p/q, where q is not equal to zero.
An integer is a number which can be positive or negative or zero. Integers are numbers which cannot be decimals or fractions. They are either whole numbers or negative numbers.
2/5 is not an integer. Since we cannot express 2/5 without a fractional or decimal point.
-5/-5 is an integer. If we simplify -5/-5 to its lowest form we get 1 which is an integer.
Therefore, every integer is a rational number but every rational number need not be an integer.