Equivalent fractions are fractions that look different but represent the exact same amount or value. They are equal to each other.
If you have a pizza cut into 2 slices and you eat 1 slice, you've eaten 1/2 of the pizza. If you have the same pizza cut into 4 slices and you eat 2 slices, you've eaten 2/4 of the pizza. Both 1/2 and 2/4 are equivalent fractions because they both mean half of the pizza.