A bijective function is a type of function that establishes a one-to-one correspondence between elements of two sets. This means that every element in the first set is paired with exactly one unique element in the second set, and vice versa. In simpler terms, no two elements from the first set map to the same element in the second set, ensuring that both sets have the same number of elements. Bijective functions are important in mathematics because they allow for the creation of inverses. If a function is bijective, you can reverse the mapping, meaning you can find a function that takes elements from the second set back to the first. This property is essential in various fields, including algebra, calculus, and computer science.