The USB 1.1 was first introduced in the year of 1998.USB version 1.1 is an upgrade from the first permutation of the USB1.0. USB 1.1 has data speed of 12 Mbits/s for the high speed cables and 1.5 Mbits/s for the normal speed and power speed of 2.5 watt. USB version 1.1 fixed those problems found in 1.0. Most of the problems generally related to the hubs. This was the earliest version of USB to be widely distributed and put into use.
The USB 2.0 was released in the year of 2000.This USB 2.0 made many improvements over USB 1.1. The main improvement of USB 2.0 has a maximum signaling rate of 480 Mbits/s due to bus access constraints the effective throughput is limited to 35 MB/s or 280 Mbits/s.USB 2.0 has power speed of 5watt. It provides additional bandwidth for multimedia and storage application and has a data transmission speed 40 faster times faster the USB 1.1. USB 2.0 and older models are only capable of processing data in a single direction at a time.