1. Bit

• The fundamental unit of memory inside a computer is called a bit, which is a contraction of the words binary digit.

• Thus, a bit is a binary digit; i.e., a 0 or 1.

• Everything is stored on the computer in units of bits.

• Because most data communications is serial in nature, most data communication and networking services indicate capacity in unit of bits per second; e.g., Ethernet operates at 10 million bits/sec (Mbps).

• Some communication schemes, such as Fibre Channel, are parallel and describe capacity in terms of bytes/sec. but that is less common.