SaaS (Software as a Service) means you use an application over the internet that someone else runs: Gmail, Slack, Figma, Salesforce. You pay (often per seat or usage); they handle servers, updates, uptime, and backups — in exchange you accept lock-in, their roadmap, and data residency on their terms unless you negotiate enterprise deals.
Real companies mix all three: SaaS for email, PaaS for your API, IaaS for a legacy box.
Most SaaS is multitenant: many customers share the same codebase and often the same clusters, isolated by accounts, schemas, or row-level security. You rarely get a dedicated server unless you pay for enterprise “single-tenant” or “VPC peering” style products.
Hyperscalers sell managed storage, databases, functions, and container orchestration as APIs + consoles. You do not rack servers; you click or call APIs and get billed. The COFFEE-PRO folders in this course — COFFEE-STORAGE, COFFEE-DATABASE, COFFEE-FUNCTIONS, COFFEE-CONTAINERS, COFFEE-DEPLOY — contain static POC UIs that mimic those consoles so you learn concepts without opening a paid cloud account (yet).
These pages are not wire-for-wire clones of AWS/GCP. Treat them like flight simulators: same instruments, different physics until you wire real credentials.
SaaS / managed cloud trades control and predictable long-run cost for speed and outsourced ops. Coffee Server is the opposite pole: your process, your disk — you are the ops team.