The amazing goroutines¹ needs something for data exchange and this is where Golang Channels come into play. They are more or less behave like FIFO circular queue.

go func (){
	time.sleep(time.Minute)
	print("world")
}

print("hello ")

ch := make(chan int, 1)
ch <- 3   // sends 3 to the channel
v := <-ch // receives 3 from the channel and assigns it to v

• Buffered Channels (Asynchronous Communication): ch := make(chan int, 3)
• Unbuffered Channels (Synchronous Communication): ch := make(chan string)
• Signalling Channels (Async Channels with Zero-sized Elements): ch:= make(chan struct{})

package main

func main() {
	tick := time.Tick(100 * time.Millisecond)
	boom := time.After(500 * time.Millisecond)
	for {
		select {
		case <-tick:
			fmt.Println("tick.")
		case <-boom:
			fmt.Println("BOOM!")
			return
		default:
			fmt.Println("    .")
			time.Sleep(50 * time.Millisecond)
		}
	}
}

• Channels are blocking for reading and writing
• Can be directed recvCh := make(<-chan int)
• Do not share memory (data is copied to the channel struct)
• Have to be closed or are blocking forever
• Deadlocks possible, but could be detected

• Exploring the Depths of Golang Channels: A Comprehensive Guide
• Golang: channels implementation
• Default Selection