As specified in RFC5735, this is an address from the "link local" block. It is assigned to a network interface as a temporary address, for instance if no static address is configured and the DHCP server is not found.
If you boot your PC without a network cable, you'll probably end up with a 169.254.*.* address.
Wiring diagrams enable technicians to tracing electrical circuits, components, and their connections.
Sorry for this but to be honest we do t get taught this in the school I go to sorry