What is meant by north, south, east and west side of the motherboard?

Historically, the northbridge was one of two main chips on the motherboard (northbridge and southbridge), and handled communication between the CPU, RAM and PCI(e) slots.
Nowadays, this functionality is typically already integrated into the CPU, but the concept of “north”, “south”, “east” and “west” is still commonly used for orientation on a motherboard or CPUs installed on the motherboard.

Motherboards with a rotated layout

Some motherboards have the socket and RAM layout rotated by 90 degrees, but even in this case the north side will be at the top when the I/O connectors are towards the left.