Rxjs is a library for reactive programming using observable streams. It provides tools for working with both synchronous and asynchronous data streams, including subscribing to and unsubscribing from streams, creating streams from arrays with "of", and transforming streams using operators like "map", "filter", and "do". Examples demonstrate mapping and filtering streams of data. Resources include the Rxjs GitHub for documentation and an introduction to reactive programming, as well as a video on viewing everything as a stream.