Hash functions are a fundamental part of modern programming. They map a variable-sized input to a fixed-size output.

We can use them to:

• Verify the integrity of files and make sure they have not been modified.
• Save a password in a database without the risk that if somebody steals the data, they will be able to know the passwords.
• Create a hash table to store items. With that, we can find them faster and using less memory.

Remember, this is just an introduction!