Although the title is weird and confusing this is what I mean. If you upload your code to for an arduino uno for example how could you run the code to do something without it being attached to the Ian which is obviously connected to the computer. Thx

you mean as a standalone? you could use a pro mini with a battery pack..

have a look at these vids..

What does the LAN have to do with this?

Arduinos can run without having to connect to a computer - all the boards provide a pin for an external non-regulated input (typically 7~12v), or can be powered direct from 5v (best way to do this on boards that have USB is to use USB cable to power from cell phone charger).

Thank you! Both were very useful thx!