Wifi is a technology for Wireless Network with devices based on IEEE802.11 So ,You do not need to stick any LAN Cable using wifi network . You Can access internet anywhere without any Ethernet Cable.
Here I will show you how to view wifi password in windows this is pretty simple ,
Step 1 . Type ncpa.cpl in run
Step 2. You will see Network here
Step 3 . Right click on wifi network and Select Status then This window will open
Step 4. Click on wireless property and select security tab
Step 5. Click on show character Then you will be able to see the password here