You already use SaaS every day — your email, your video calls, the tools your company runs on. But what exactly is SaaS, why did it take over software, and what does it mean if you're thinking of building or buying it? Here's a clear explanation.

What SaaS means

SaaS — software as a service — is software you access over the internet, usually for a subscription, instead of installing and owning it. The provider runs everything — servers, updates, security — and you just log in through a browser. Gmail, Slack, Shopify and Salesforce are all SaaS.

SaaS vs traditional software

Traditional software was bought once, installed on your machine, and went stale until you paid for the next version. SaaS flipped that: you pay over time, you always have the latest version, and you reach it from any device. The vendor's job never ends — they keep improving the product you rent.

Why SaaS won

  • No big upfront cost — subscriptions instead of large licences.
  • Always up to date — improvements arrive continuously.
  • Accessible anywhere — browser and cloud, any device.
  • Scales with you — add users or features as you grow.
  • Less IT burden — the provider handles infrastructure.

How SaaS businesses make money

Through recurring revenue — monthly or annual subscriptions, often tiered by features or users. Because revenue recurs, two numbers rule the SaaS world: how much it costs to acquire a customer, and how long that customer stays (retention). Keeping customers matters as much as winning them.

Common SaaS terms, demystified

  • MRR / ARR — monthly / annual recurring revenue.
  • Churn — the rate at which customers leave.
  • Freemium — a free tier that upgrades to paid.
  • Multi-tenant — many customers served from one shared system.

Is SaaS right for your business?

As a buyer, SaaS usually means lower risk and faster setup. As a builder, SaaS is one of the most attractive models in tech — recurring revenue and the ability to improve one product for everyone — but it demands ongoing investment in product, support and retention. It's not "build it and forget it." For how that build works, see how digital products are really made.

How Pupal helps

We build SaaS products — our own (Clinicon, Velan 360, Onlives) and for partners. If you're considering a SaaS product, our SaaS & products and web development services are where to start.