Types and Methods of Data Transmission

Data transmission is how binary data travels between two devices over a wired or wireless link. Almost every computer activity relies on it: clicking a key sends data from the keyboard to the CPU; opening a web page sends data across the internet; printing a document sends data from the computer to the printer.

This topic covers four big questions:

1. How is data broken up and routed across a network? (Packets and packet switching.)
2. Are the bits sent one at a time or many at once? (Serial vs parallel transmission.)
3. Can data flow both ways, and if so, simultaneously? (Simplex, half-duplex, full-duplex.)
4. What is the most common wired connection in everyday use? (USB.)

Two more terms describe how fast a link is: bandwidth (capacity) and latency (delay). They turn up in every comparison.