What Is a Channel?

Many of us are eager to finally hear about Flow, also known as coroutines’ reactive streams. In the following chapters, we will learn about Channel and Flow, both of which are valuable tools worth knowing about. We’ll start with Channel, as it’s a bit more of a basic concept, then we’ll get deeply into learning about Flow.

Channel

The Channel API was added as an inter-coroutine communication primitive. Many imagine a channel as a pipe, but we prefer a different metaphor, such as exchanging books at a public library. One person needs to bring a book back so it can be put on the shelf and another person can find it. This is very similar to how Channel from kotlinx.coroutines works.