A unit fraction is a fraction where the numerator is always 1. For example, 1/2 or 1/3 are both unit fractions.
To multiply two unit fractions together, simply multiply the numerators together and then multiply the denominators together. The resulting product is your answer.
In the area model for multiplying non-unit fractions, there is a 'crossover' part where one numerator multiplies with another denominator and vice versa. This represents the idea of multiplying the fractions together and is an important concept to understand in fraction multiplication.