How to communicate with a device?

Question

I am a web programmer and I am just wondering how software and hardware can communicate. I have basic knowledge in Java but I am not an expert.

Let's make it simple. I have a device which is just a simple lamp that can get switched on and off and it is connected via USB. My software has only one function - pressing enter.

By pressing enter I want the software to communicate with the USB port and tell it to activate the device. How would that be possible? Where do I have to start and what do I need to learn?

I understand that my question and my example sound silly but I am just trying to understand how it works.

I appreciate any help!

Answer 1

I think that if you using arduino or other prototyping board you might use rxtx serial library.