The server compares the Host header with a small virtual-host table.
The server compares Host to rows
Each virtual-host row has a host name and a site name.
route rows=3
The first row is net.example
The first row has host net.example and site net-docs.
net.example→net-docs
Other rows are still checked
The shop row does not match, and the default row is only fallback.
fallback is not first choice
Summary
A virtual-host table is a small lookup: compare the Host header to configured rows.
Host compared to rows