1.) Modem stands for modulator-demodulator.
2.) The Speeds
 Dial Up: 56Kbps
 DSL: 384Kbps
 Cable:768Kbps
 T1: 1.5Mbps
 T3: 6Mbps.15Mbps, 30Mbps
3.) It goes through the telephone lines. It uses a modem.
4.) Start bit describes an asynchronus transmission protocol where  start signal is sent prior to each byte, character or code word and a stop signal is sent after each code word. Stop bits are a way for a computer to "catch its breath" while sending or receiving data. Parity bits are binary digits that indicates whether the number of bits with value of  one in a given set of bits is even or odd. There used as the simplest error detecting code. There’s two types, one is even and one is odd. The even 
5.) Baud is a measure of the symbol rate.