When handling multiple asynchronous tasks in JavaScript, you often need to coordinate how their results are collected or how errors are handled. Promise combinators provide different strategies for working with multiple promises at once. The main combinators you have learned about are Promise.all, Promise.race, Promise.allSettled, and Promise.any. Each serves a distinct purpose, and understanding their differences will help you pick the right tool for your asynchronous workflows.

Promise.all is designed for situations where you want to run several promises in parallel and need all of them to complete successfully. If any promise in the array rejects, the entire Promise.all call immediately rejects with that error, and you do not get the results of the other promises. This all-or-nothing approach is useful when every result is required before continuing.

On the other hand, Promise.race waits for the first promise in the array to settle, whether it fulfills or rejects. As soon as any promise completes, its value or error is returned, and the rest are ignored. This is helpful when you want the result of the fastest operation, regardless of whether it succeeded or failed.

If you need to know the outcome of every promise, regardless of whether they fulfilled or rejected, Promise.allSettled is the right choice. It waits for all promises to settle and returns an array of objects describing the outcome of each one. This is especially useful when you want to handle successes and failures individually after all tasks have finished.

Finally, Promise.any is useful when you want to proceed as soon as any promise fulfills. It ignores rejections unless every promise fails, in which case it rejects with an AggregateError. This makes it ideal when you only need one successful result and do not care which one it is.