My goal here is to walk through my process of building react from the groundup, hopefully giving you an intuition to why things behave the way they do in react.

Pros and cons of Database identity
Nice to work with in URLs
Limiting, as they require a trip to the database, which precludes some patterns
Can be tricky to return IDs when inserting in some cases (EF Core etc solves this)
Can cause contention in high throughput scenarios. May make scaling out impossible

Code rules are rules that the compiler or code analysis tool enforces at the build level

how-web-browsers-work-part-1-with-illustrations