What does this 'buffer' do in this function

In my Google search I find this function:


var InputSource = function(stream) {
	var buffers = [];
	.
	.
	.
	if (this.ws) { // only have websocket set
		binary.pack({
			ch_num:buffers.length,
			buffer_length:BUFFER_LENGTH,
			buffer_array:buffers
		}, function(buffer) {
			this.ws.send(buffer);
		});
	}
};

I wonder what does this ‘buffer’ mean or what it does?

There is a global declaration var buffer = [, ]; outside the function.

The code is three hundred lines long but this is the part which I want.

Thanks

Note: I don’t use their code. I want to create my own code but I don’t know what does this mean.

Never Mind. Despite not understand this, I got the result I want.