Twin primes are pairs of prime numbers that have a difference of two. For example, the pairs 3, 5, 11, 13, and 17, 19 are all twin primes. A prime number is a natural number greater than one that has no positive divisors other than one and itself. The study of twin primes is a part of number theory, a branch of mathematics that explores the properties and relationships of numbers. While there are infinitely many prime numbers, it remains an open question whether there are infinitely many twin primes, a topic that has intrigued mathematicians for centuries.