"your computer must be connected to the same wifi network"?

How does companion connect to my computer via wifi? my companion device obviously has no wired connection, but my computer does (and does not have a wifi connection). if both devices are connected to the internet will that work? Can the connection be made from the computer to the companion device (so a firewall port doesn't have to be opened), or am i required to open a firewall port for the wifi device to connect to the computer?

Welcome

The information in this link may answer your question http://appinventor.mit.edu/explore/support/explain-wifi-connection

Does it help?