Prime numbers matter a lot in our daily lives and we often don't even realize it. Much of the foundation of cryptography and public keys, so prevalant in our digital systems, are extremely dependent on prime numbers. In the early 2000s a team of IIT Kanpur researchers discovered the AKS Algorithm and published a "Primes is in P" paper  an unconditional deterministic polynomialtime algorithm that determines whether an input number is prime or composite.
A prime number is a whole number greater than 1 whose only factors are 1 and itself. The first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29. Numbers that have more than two factors are called composite numbers. A factor is defined as a whole numbers that can be divided evenly into another number. The Sieve of Eratosthenes is a very simple and popular technique for finding prime numbers. You might also find it useful to read more about prime factorization here.
Prime numbers and various topics based on them are an important part of junior school mathematics all over the world  right from Common Core standards in the United States, ICSE/CBSE systems in India, Cambridge and GCSE curriculum schools in the UK.
