It means you're not managing a server OS. You're not even building a container. You're defining a function (as in, "fn foo(a, b): return a+b") which is called i

It means you're not managing a server OS. You're not even building a container. You're defining a function (as in, "fn foo(a, b): return a+b") which is called in somebody else's environment, and they have complete control over how your function is run - you're not dealing with autoscaling or whatever yourself.