Both systems central focus is a "Router". Most common Wi-Fi routers have 4 "RJ-45" LAN cable ports on them, so they can be used as a wired network as well... they just add the antenna(s) and circuitry for the radio broadcast (Wi-Fi) part.
Unfortunately, when you radio broadcast your data (or anything for that matter), it means that anyone in range can intercept it, and possibly decrypt it. A number of folks don't even have "secured" Wi-Fi networks.
It is a good idea to do your homework, and know and understand something about Wi-Fi security, before you try and connect to and use a Wi-Fi network.
You should at least be able to identify if you are connecting wirelessly. It is entirely possible to be connected both through a wired and wireless connection at the same time, so simply connecting your PC to a router with a cable does not necessarily mean that you are disconnected from the Wi-Fi part... and if the Wi Fi is not secure (or even if it is), there is a possibility that you are broadcasting sensitive information.
https://www.google.com/search?q=wireless+network+security+protocols
The two most popular Wi-Fi Security Protocols in use today (Feb-2013) are:
WEP
WPA2-PSK (which has several different variations)
Try reading:
The Differences Between WEP and WPA
... while the publication date is old, it is still a very easy to read article, which pretty clearly explains the differences here. One significant nugget here is:
"Researchers in the computer science department of a German university recently demonstrated the capability to compromise a WEP-protected network very quickly. After spending less than a minute intercepting data (fewer than 100,000 packets in all) they were able to compromise a WEP key in just three seconds."https://www.google.com/search?q=how+secure+is+a+wireless+computer+network
Even the most secure household Wi-Fi Computer Networking are not necessarily all that secure. Some major problems in using an unsecured network include:
- Unauthorized use of your Network by neighbors, of people on the street or in parking lots.
- Ability of intruders on your network to access your files, data, and possibly even "secure" website connections (e-mail, banking, etc.) where you "saved" the log-in info to your browser.
- Allowing intruders to use your unsecured (or poorly secured) PC Network to upload illegal materials to the Internet, which can be traced back to you... and could bring an agency such as the FBI knocking at your door.
So... A word to the wise... Again...
Do your homework... and know how to test that your WI-Fi network is secure.
Another good topic to followup on is:
Have fun!
===================================================
