(1) (Built-In Test) See BIST.
(2) (BInary digiT) The smallest element of computer storage. It is a single digit in a binary number (0 or 1). The bit is physically a transistor or capacitor in a memory cell, a magnetic domain on disk or tape, a reflective spot on optical media or a high or low voltage pulsing through a circuit.
Bits for Transmission
Bits are widely used as a measurement for network transmission. One hundred megabits per second means that 100 million pulses are transmitted per second.
Bytes for Storage
Groups of bits make up storage units in the computer, called "characters," "bytes," or "words," which are manipulated as a group. The most common is the byte, made up of eight bits and equivalent to one alphanumeric character. Measurements for storage components, such as disks, files and databases, are given in bytes rather than bits. See space/time.
Storage - Making it Smaller
Making the spot or cell smaller increases the storage capacity. Our disks hold staggering amounts of data compared to 10 years ago, yet we still want more. Look up holographic storage
for a look into a fascinating future of storage technology.
Transmission - Making it Faster
The bit is transmitted as a pulse of high or low voltage. Speed is increased by making the transistors open and close faster, which is a combination of making the microscopic elements within the transistor smaller and more durable.
Transmitting pulses internally in the computer is much simpler than out over a network, where they are influenced by long distances and interference. The telephone companies pioneered the deployment of high-speed optical trunks, which overcome some of these limitations.