1. RxSwift provides reactive extensions for Swift that allow composing asynchronous and event-based programs using observable sequences and functional style operators.
2. Operators like observeOn and subscribeOn allow controlling the scheduling of work and observation across different threads using Schedulers. ObserveOn changes the scheduler an observer uses for notifications, while SubscribeOn changes the scheduler an observable uses for subscription.
3. Drivers in RxCocoa provide a way to connect observables to the UI by implicitly subscribing on the main thread and preventing errors from crashing the app.