A factor rate is a multiplier applied to the amount you receive. For example, a 1.30 factor rate on $100,000 means a total payback of $130,000.
Unlike APR, a factor rate does not include time. The time you take to repay changes the effective annualized cost a lot.
Before you accept an offer, ask for the total payback, the estimated term, the holdback percentage, and all fees itemized.