We have a credit line now, but often times if you're a new-ish business, banks aren't too keen on giving you one (especially if you are cashflow negative). So sometimes you have to go to places like Kabbage or other pseudo-payroll lender type places who charge insane APRs for short-term bridge financing.

Functions pretty similarly, except one is a reputable business (banks... well, kinda reputable) and the bridge loan shops tend to be pretty maligned (and often reasonably so).