A “hash” is like a digital fingerprint for a piece of data (like a file, a password, or a digital certificate). It’s created by a special mathematical formula (a hash function).
You put your data into the function, and out comes a unique string of characters (the hash). Just like a fingerprint is unique to a person, a hash is (almost always) unique to a specific piece of data. If you change even a tiny part of the original data and put it through the hash function again, you’ll get a completely different hash.
When it comes to digital certificates (like the ones used to secure websites), a hash can help make sure the certificate is genuine and hasn’t been tampered with.
It’s a bit like the seal on a jar of pickles. If the seal is broken, you know someone might have tampered with the contents. If the hash doesn’t match what it should be, you know the certificate may have been altered.
Remember, all of this happens behind the scenes when you’re browsing the internet. It’s part of the magic that keeps your information safe online!