Title explains it.

Imagine this example, Host computer connects to a Client computer via male/male usb connection. Client computer acknowledges this connection as a new device, in this case a keyboard. The host computer can now send key events to the client computer and the client computer would process them as a normal keyboard event.

I did a whole lot of searching in the internet and really have drove down many dead ends. Any tips would be appreciated.

Note* this is a physical connection. The client computer should not have to install any software for this to function (The host will completely spoof as a keyboard).