Cosm is a website to which you send information, just like this one, but you do it directly from your Arduino. It may be possible to send a feed from your PC but I can't see the point, and it is made specifically for microcontrollers. You therefore need an Ethernet facility, be it a shield or built-in. I don't know what you are talking about or the devices you allude to but, if you can send data from them to your local display, you can send the same or similar data to cosm.
Cosm displays a graph for each feed. It is typically a variable or an event against time. An example https://cosm.pachube.com/feeds/83153
The action is not live, the viewer must refresh the screen manually.