GUIDs pop up everywhere in software!
For a lot of us it's just a seemingly random 128 bit number that's normally printed out in a particular format. But their are actually a few different kinds of GUIDs each following a specific structure as described in RFC 4122.
You can use this site to generate GUIDs, understand how they are constructed, or parse existing GUIDs. If you really want to get to know GUIDs check out the open source GUID generator that powers the site here.
A GUID or UUID is a 128-bit unique reference number used in computing, a GUID follows a specific structure defined in RFC 4122 and come in a few different versions and variants.
Interested in the nuts and bolts of how GUIDs are created? We'll give you a nice overview so you don't need to get too bogged down in the spec.
Sites like this are great for quickly generating a GUID or two - but most development environments have inbuilt tools or commands which are quicker to use on a regular basis.