how you connect to net

i saw two ways for net connection in two different countries i lived in . the first way is throgh the phone line .. i.e you have a phone line socket in the wall ... that socket accepts RJ 11 , connecting the wire b/w phone device and socket will run the phone . in net .. a splitter that splittes the RJ11 line comes from wall is used to produce to lines , one for phone and the other...