Channels are the second primitive in the language that allows us to write concurrent applications. We have talked a bit about channels in the Communicating sequential processes section.
Channels are the way we communicate between processes. We could be sharing a memory location and using mutexes to control the processes' access. But channels provide us with a more natural way to handle concurrent applications that also produces better concurrent designs in our programs.
Working with many Goroutines seems pretty difficult if we can't create some synchronization between them. The order of execution could be irrelevant as soon as they are synchronized. Channels are the second key feature to write concurrent applications in Go.
A TV channel in real life is something that connects an emission (from a studio) to millions of TVs (the receivers). Channels in Go work in a similar fashion. One or more Goroutines can work as emitters, and one or more Goroutine can act as receivers...