Rational numbers are any numbers that you can rewrite as a fraction. Irrational numbers are numbers that we can't really write down the exact value of them. I'll show some examples.
1/2 is a rational number because it can be written as a fraction. We know it can be it's already in fraction form which is a/b. Another example would be the decimal 1.6 which would also be a rational number.Since 1.6 can be written as the fraction 8/5, we would classify this as a rational number.
π is an irrational number that goes on forever so it's impossible to write down the exact value of π so we represent it using the symbol. Another example would be the square root of 47. When you type in the square root of 47 on a calculator, you get . a decimal approximation which keeps going on and on . forever which means that it's an irrational number. This is because irrational numbers can also be classified as all decimals that are non-terminating & non-repeating.