You learned about the different promise states:

• PENDING => Promise is doing work, neither then() nor catch() executes at this moment

• RESOLVED => Promise is resolved => then() executes

• REJECTED  => Promise was rejected => catch() executes

When you have another then() block after a catch() or then() block, the promise re-enters PENDING mode (keep in mind: then() and catch() always return a new promise - either not resolving to anything or resolving to what you return inside of then()). Only if there are no more then() blocks left, it enters a new, final mode: SETTLED.

Once SETTLED, you can use a special block - finally() - to do final cleanup work. finally() is reached no matter if you resolved or rejected before.

Here's an example:

somePromiseCreatingCode()
    .then(firstResult => {
        return 'done with first promise';
    })
    .catch(err => {
        // would handle any errors thrown before
        // implicitly returns a new promise - just like then()
    })
    .finally(() => {
        // the promise is settled now - finally() will NOT return a new promise!
        // you can do final cleanup work here
    });

You don't have to add a finally() block (indeed we haven't in the lectures).