A hosting model where you deploy individual functions or containers and the cloud provider runs them on demand, scaling to zero when idle. You pay per execution rather than for a server that runs all month.
For spiky or low-volume workloads — scheduled jobs, webhook handlers, image processing — serverless removes both idle cost and server maintenance. For steady high traffic it usually ends up more expensive than a plain server.
We use serverless for background and event-driven work alongside a conventional application, and we measure cost at expected volume before committing, because the pricing model punishes chatty designs.