Data rate and data transfer rate can refer to several related and overlapping concepts in communications networks:
Achieved rate Bit rate, the number of bits that are conveyed or processed per unit of time Data signaling rate or gross bit rate, a bit rate that includes protocol overhead Symbol rate or baud rate, the number of symbol changes, waveform changes, or signaling events across the transmission medium per unit of time Data-rate units, measures of the bit rate or baud rate of a link Data transfer rate (disk drive), a data rate specific to disk drive operations Throughput, the rate of successful message delivery, or level of bandwidth consumption Transfers per second
Capacity Bandwidth (computing), the maximum rate of data transfer across a given path Channel capacity, an information-theoretic upper bound on the rate at which data can be reliably transmitted, given noise on a channel