Short answer
The subclass 494 visa is a temporary regional employer-sponsored visa that can lead to subclass 191 permanent residence.
The visa is for regional employers who genuinely cannot find an appropriately skilled Australian worker. It has an Employer Sponsored stream and a Labour Agreement stream.
The visa is provisional and can let the primary holder stay in Australia for five years from approval. It is intended to support a later subclass 191 permanent residence pathway after the required period is met.