If the particular IP is configured locally on a network interface, the server will match the IP you give it to the interface the IP lives on. It will then only listen for traffic coming via that device. (It won't need to go 'check' on the network).
This can be a good security measure, for instance if you have a service which is only needed locally (e.g. MySQL), don't bind it to your internet-facing interface.
Normally if you give a service an IP that doesn't exist locally it will return an error along the lines of "failed to bind to X". However there are some situations where you need to a service to bind to an IP that may not currently existing on the service. An example is in a highly-available setup, where IPs can move between servers.
In that case the sysctl setting
net.ipv4.ip_nonlocal_bind will let you do so without an error.