The Symfony UID component has been released one year ago as a simple OOP layer on top of the "uuid" extension and polyfill. Since then, it has matured from experimental to stable and has increased the range of use cases it can fulfill, while keeping a clean and simple design.

But what are "UIDs" in the first place? Unique IDentifiers serve many purposes! During this talk, we will explore the component itself. We will also discuss the various types of UIDs and when each of them should be preferably used.

Last but not least, we will make this an opportunity to discuss why the Symfony project decided to create a new component on the topic, while alternatives exist.