8 pin relay pin configuration
As others have stated it is a dual/double pole relay. That is there are two independent three-way, or dual-throw, switches inside the relay. It is properly named a Double-Pole-Dual-Throw DPDT relay.

If it helps, the diagram below may be easier to understand.







simulate this circuit &ndash; Schematic created using CircuitLab

Interestingly they numbered the pins to include the missing pins 2, and 11, and left room to include the second coil on pins 6 and 7 for the dual coil latching type. So in effect it is a 12 pin part. Designing your PCB that way makes changing the style of relay later much easier.