Autoscaling is supposed to save money. A lot of the time it doesn't, because people reach for the wrong kind. Kubernetes gives you three common options, and they solve three completely different problems. Pick the wrong one and your bill barely moves.
Here's a plain breakdown of HPA, VPA, and KEDA, what each actually does to your cloud spend, and the one thing that decides whether any of them saves you a rupee.
The one-line difference
HPA changes how many pods you run. VPA changes how big each pod is. KEDA makes pods appear and disappear based on events, and can take them all the way to zero. That's the whole mental model. Everything below is detail.
HPA: more pods when it's busy, fewer when it's not
