ISO/IEC 8859 in the context of 8-bit processor

Character encoding is a convention of using a numeric value to represent each character of a writing script. Not only can a character set include natural language symbols, but it can also include codes that have meanings or functions outside of language, such as control characters and whitespace. Character encodings have also been defined for some constructed languages. When encoded, character data can be stored, transmitted, and transformed by a computer. The numerical values that make up a character encoding are known as code points and collectively comprise a code space or a code page.

Early character encodings that originated with optical or electrical telegraphy and in early computers could only represent a subset of the characters used in languages, sometimes restricted to upper case letters, numerals and limited punctuation. Over time, encodings capable of representing more characters were created, such as ASCII, ISO/IEC 8859, and Unicode encodings such as UTF-8 and UTF-16.

In computer architecture, 8-bit integers or other data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data buses of that size. Memory addresses (and thus address buses) for 8-bit CPUs are generally larger than 8-bit, usually 16-bit. 8-bit microcomputers are microcomputers that use 8-bit microprocessors.

The term '8-bit' is also applied to the character sets that could be used on computers with 8-bit bytes, the best known being various forms of extended ASCII, including the ISO/IEC 8859 series of national character sets – especially Latin 1 for English and Western European languages.

Transcoding is the direct digital-to-digital conversion of one encoding to another, such as for video data files, audio files (e.g., MP3, WAV), or character encoding (e.g., UTF-8, ISO/IEC 8859). This is usually done in cases where a target device (or workflow) does not support the format or has limited storage capacity that mandates a reduced file size, or to convert incompatible or obsolete data to a better-supported or modern format.

In the analog video world, transcoding can be performed just while files are being searched, as well as for presentation. For example, Cineon and DPX files have been widely used as a common format for digital cinema, but the data size of a two-hour movie is about 8 terabytes (TB). That large size can increase the cost and difficulty of handling movie files. However, transcoding into a JPEG2000 lossless format has better data compression performance than other lossless coding technologies; in many cases, JPEG2000 can compress images to half their original size.