Concurrency

Concurrency can mean different things depending on the context.

In local rendering, concurrency refers to how many browser tabs are opened in parallel during a render.
Each Chrome tab renders web content and then screenshots it.

For rendering on Lambda, concurrency refers to the amount of Lambda functions that are spawned for a render. You can control the Lambda concurrency using the framesPerLambda option.

Each Lambda function usually opens just a single tab, unless you use the concurrencyPerLambda option to increase the amount of tabs per Lambda function.

Higher concurrency can lead to faster render times, but too high concurrency will lead to diminishing returns and to overload of the machines, which might crash a render.