Is the subclass 188 a permanent visa, or only temporary?

The subclass 188 is a provisional visa, meaning it is temporary and valid for a set period. It lets you establish and maintain business or investment activity in Australia.

Permanent residence comes through the separate Business Innovation and Investment (Permanent) visa (subclass 888), which you can apply for after holding the 188 and meeting that stream's requirements. Holding the 188 alone does not make you a permanent resident.