为什么Go App要作为多个进程运行？

I have a very simple program written in go:

package main

import (
    "fmt"
    "time"
)

func main() {
    fmt.Println("hello")
    time.Sleep(5 * time.Second)
    fmt.Println("good bye")
}

Now I'm building it using "go build .". When I look at htop to see the application running, it shows me that several processes are being executed on my machine.

Can someone explain to me why is that happening? I would expect a single goroutine program to run as single process.

Can someone explain to me why is that happening?

Yes. You are either using htop or top with H which shows threads. Your program uses several threads like any Go program (see also Pizza lord's comment).