What is Bitstream?
Bitstream meaning in Digital terms is Contiguous or non-contiguous data within a file that has meaningful common properties for preservation purposes. Generally speaking, a bitstream cannot be transformed into a standalone file without the addition of file structure (headers, etc.) and/or reformatting the bitstream to comply with some particular file format. This definition is derived from the data model outlined in Introduction and Supporting Materials from PREMIS Data Dictionary, p. 7, illustrated by the example of a TIFF file that contains embedded bitstreams representing raster images together with header that presents some information about the file. The authors of the PREMIS definition note that their definition is limited to sets of bits embedded within a file and they call attention to an alternate usage that defines bitstream as an entity that could span more than one file.