In WCM we recommend using the provided tooling to link content, resources, components, ect.
We urge end users not to hard code the reference URLs, because the UUID of elements stored in content may change.
Here is an example.
A File Resource Component has an underlying file resource attachment (or element)
When it is moved to a different environment via syndication, export/import, migration.
The underlying file resource internal ID may change.
This will cause your reference links to break if hard coded URLs are being used.
If the provided tooling was used to create the reference links.
The links will automatically transform when moved to the new server.