An equivalent fraction is a fraction that has the same value as another fraction but they have different top and bottom numbers.
Let's look at an example.
In the image provided, I have attached a picture of two figures.
Since the first figure has 1 out of 6 rectangles shaded and the second figure has 2 out of 12 rectangles shaded, we can see that the fractions 1/6 and 2/12 must be equivalent.
Notice that 1 x 2 is 2 and 6 x 2 is 12 so multiplying or dividing the numerator and denominator by the same number will give us an equivalent fraction.