Not to insult your intelligence but, you know the signal on the wire is just a bunch of wiggles with the electricity going up and down. Each possible wiggle is a Bit"binary digit", where going up is a one and going down is a zero,(sort of). Well, for some reason the computer world decided to communicate in groups of 8 wiggles(sort of) at a time and call it a Byte. What do you get if you divide 1.5 million wiggles (per second) by 8? 187,500 bytes (per second). These are the number of Bytes in 1.5 million bits. You are not going to get the wiggles to happen that fast(@1.5). Several things between the source of the signal and you tend to slow things down but faster if better.