Data transmission

Data transmission is the process of transferring data from one point to another. There are two methods for transmitting data: Serial communication and Parallel communication. There are different types of devices for data transmission: Wireless, Optical fiber, Infrared and more.
Simplex data transmission
is in one direction only (i.e. from sender to receiver). Example: data being sent from a computer to a printer. 
HALF· DUPLEX DATA TRANSMISSION
is in both directions but not at the same time (i.e. data can be sent from 'A' to 'B' or from 'B' to 'A' along the same line, but not at the same time). Example: a phone conversation between two people where only one person speaks at a time .
FULL·DUPLEX DATA TRANSMISSION
is in both direction simultaneously (i.e. data can be sent from 'A' to ' B' and from 'B' to 'A' along the same line, both at the same time). Example: broadband connection on a phone line.