Why do we need to run unbuffered channels in go routine but buffered channels can work without go routine?

Question

I was going through tutorials on gobyexample. I noticed the author has shown example of gochannel using go routine but in buggered go channel he is directly sending messages to channel .

I tried on my local system to run unbuffered channel without go routine but it is throwing "fatal error: all goroutines are asleep - deadlock!" but buffered channels are working fine without go routine

func channelDemo() {
    message := make(chan string)
    // go func() {
    //  message <- "Hello"
    // }()
    message <- "Hello"
    msg := <-message

    fmt.Println("msg", msg)
}
func channelBufferingDemo() {
    messages := make(chan string, 3)

    messages <- "Buffered"
    messages <- "channel"
    fmt.Println(<-messages)
    fmt.Println(<-messages)
}

Answer 1

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