During open enrollment, a benefits Lambda sees many overlapping invokes. How should the developer explain concurrency versus reserved concurrency?
Select an answer to reveal the explanation.
Short Explanation
Picture open-enrollment as checkout lanes: concurrency is how many cashiers are ringing at once. Reserved concurrency puts a hard cap—and a reserved slice—on one function so it can't hog the whole store. That's how you keep one hot path from starving siblings.
Full Explanation
Lambda concurrency counts simultaneous executions. Reserved concurrency both limits a function's maximum concurrent executions and reserves that capacity from the account pool, which matters during traffic spikes such as open enrollment. It is unrelated to package size, does not disable all account scaling by itself, and is not an EC2-only concept.