If you are not familiar with Software as a Service business models and how SaaS companies work this primer from Stripe covers on all the main concepts.

… we’ll take you through a whirlwind tour of the state of play of SaaS businesses. You should gain a better understanding of the SaaS business model, be able to anticipate whether to sell your product on a low-touch or high-touch model, and be able to evaluate its health and start improving it.