wi-fi - wi-fi is what you have to connect to too get on the internet anywhere. Anything can connect to it from Laptop to Phones and iPad's and you have to be in the house to connect it.
3G- 3G is when you don't have to be connected to the modem in your house. The good thing is that you can still go on the internet without being connected with the modem.
Bluethooth_ Bluethooth is when you can make friends with someone and send them videos,images and songs though Bluethooth.
SMS- SMS is simple message service and is a simple text through analog.
MMS- Is multi media service and changes when you put a photo into it and the person receives it by the messages going through 3G or WI-FI
