How does Maps on Mac OS determine the computer's location

How does Maps on Mac OS finds the computer's location so precisely?

There is no GPS chip on the Mac, so how does it really work?

Can someone provide details about the process used by the Mac OS location services?

Ideally some logs or dumps of communication data between the mac and the servers would be great.

Apple is using Core Location code that's mostly common to iOS and OS X and the primary signal your Mac has to determine location is detected wireless hotspot serial numbers (SSID and MAC address if available).

Also, by tracing the IP address for Macs with active connections to the internet, often that will at least get you in the proper time zone and occasionally in the proper zip code (or postal code for people outside the US).

Apple secretly places a GPS chip in every Mac. (j/k)

It gathers data from your IP/MAC Address and tries to look for other WiFi Access Points (even if it can't actually connect to them) to get their MAC Address and signal strength. It compares it to data in Apple's database.