Dynamic routes in next.js

1. Dynamic Segment

A Dynamic Segment can be created by wrapping a folder's name in square brackets: [folderName]. For example, [id] or [slug].

2. Catch-all Segments

Dynamic Segments can be extended to catch-all subsequent segments by adding an ellipsis inside the brackets [...folderName].

3. Optional Catch-all Segments

Catch-all Segments can be made optional by including the parameter in double square brackets: [[...folderName]].

ref: https://nextjs.org/docs/pages/building-your-application/routing/dynamic-routes