Fractions are numbers that represent a part of a whole and consist of two parts: the numerator and the denominator. There are three main types of fractions: proper fractions, improper fractions, and mixed numbers. A proper fraction has a numerator smaller than its denominator, such as 1/2. An improper fraction has a numerator larger than or equal to its denominator, like 5/4. Mixed numbers combine a whole number and a proper fraction, such as 2 1/3. Understanding these types helps in performing mathematical operations and comparing fractions effectively. Each type serves a unique purpose in various mathematical contexts.