I'll wrte in English as I type faster. In Reactor you have one object that awaits for incomming events (accpeting connections, requests to connect to someone, reading data, writing data). ONLY when there is an event the short thread processing it is created. There is a thread pool (can be adjusted to match the load), so the number of existing threads is limited. The Reactor pattern/Non-blocking IO is used to avoid having a thread per connections, which is "expensive" and can lead to DoS attacks/situations.