What is a UUID (or GUID)?

Our favorite statistically unique identifier (00000000–0000–0000–0000–000000000000)

Photo by Cristofer Maximilian on Unsplash

TL;DR

• A UUID (universally unique identifier) is a statistically unique identifier
• It looks like this: 60f9496b-621c-48d8–8cba-1ebdd866a030
• There are more possible UUIDs than there are grains of sand on Earth
• It is 128-bit value expressed as 32 hexadecimal characters plus dashes for readability
• A GUID (globally unique identifier) is what a UUID is called in the Microsoft world

Intro

In software, UUIDs (universally unique identifiers) are popular unique identifiers that look like the following examples:

• b3f2ebd3–4434–47b0–95ed-1a3f48825069
• 93c120f0-b192–43fb-bc18–2e898156d7a6
• 37e80a32-d891–4e52-bf76–016d98142545

Even if you’re not in software, you’ve likely seen these before in emails or in views in certain applications. UUIDs are prolific. Before we dive into the details of these popular unique identifiers, let’s get a little background.

What is an Identifier?

An identifier, or “ID” for short, is a label given to something in order to distinguish it from something…