Difference from classic software
In the past, you bought software like Word or Photoshop, installed it from a CD on your computer. Updates required a new CD.
In SaaS, software runs on the provider's servers. You access it through a browser. You pay monthly or annually. Updates are automatic.
Advantages
Low upfront cost: No big one-time license; you start with $20–200/month.
Automatic updates: New features arrive automatically.
Access from anywhere: Works on any device with a browser.
Scaling: If your team grows, upgrade the plan in minutes.
Disadvantages
Internet dependence: If the internet goes out, the system stops (some SaaS offer offline mode).
Vendor lock-in: Leaving a provider can be hard; data portability matters.
Long-term cost: The total of 5–10 years of subscriptions may exceed a one-time license.