What Is the Difference Between Bits and Bytes?
The size of a computer file is expressed in bytes while bandwidth is expressed in bits per second. Therefore, a file of 128 kilobytes (kB) would take eight seconds to download across a 128 kbps line. Very large files are often compressed in order to transmit them as quickly a possible. For example, full-screen live TV requires at least 10 million bits per second of data (say 200 x 300 pixels using 7-bit analogue-to-digital conversion and 24 frames per second) and so cannot be transmitted effectively, even using broadband. However by making the file smaller with compression techniques viewable video data can be sent on broadband.
