What is the use of buffered channels in Go?

Question

I understand from this question "Golang - What is channel buffer size?" that if the channel is buffered it won't block.

c := make(chan int, 1)
c <- data1 // doesn't block
c <- data2 // blocks until another goroutine receives from the channel
c <- data3
c <- data4

But I don't understand whats the use of it. Suppose if I have 2 goroutines, 1st one will received data1 and 2nd one receives data2 then it will block till any subroutines gets free to process data3.

I don't understand what difference did it make ? It would have executed the same way without buffer. Can you explain a possible scenario where buffering is useful ?

Answer 1

A buffered channel allows the goroutine that is adding data to the buffered channel to keep running and doing things, even if the goroutines reading from the channel are starting to fall behind a little bit.

For example, you might have one goroutine that is receiving HTTP requests and you want it to be as fast as possible. However you also want it to queue up some background job, like sending an email, which could take a while. So the HTTP goroutine just parses the user's request and quickly adds the background job to the buffered channel. The other goroutines will process it when they have time. If you get a sudden surge in HTTP requests, the users will not notice any slowness in the HTTP if your buffer is big enough.