Explore the model
Concurrency is the number of requests a Lambda function handles at once. For a steady workload, estimate it as requests per second multiplied by average duration in seconds. Change those controls in the visualiser to see demand fill an account concurrency pool in one Region, then watch scaling capacity and throttled requests as traffic changes.
Try reserved concurrency to set a function limit or provisioned concurrency to explore prepared capacity. Open Lifecycle & more to see optional, illustrative Init and warm reuse. This browser-only simulator makes no AWS calls. Its scaling and lifecycle model is for learning, not live account metrics or an AWS timing guarantee.
Read the source code and model assumptions or the AWS Lambda concurrency documentation.