A bitstream is a continuous sequence of bits, the 0s and 1s of binary code, transmitted over a network or read from storage as a single flow. Audio and video streams, file downloads and data sent between payment terminals and processors all travel as bitstreams, which are later decoded into meaningful messages or files. In hardware design, a bitstream is the file that configures a programmable chip, such as those used in some cryptocurrency mining equipment and high-speed trading systems. In telecoms, "bitstream access" refers to wholesale broadband services that one operator sells to another. Secure systems protect bitstreams with encryption so they cannot be read or altered in transit. Also see Bandwidth.