In computing, source code is any collection of computer instructions (possibly with comments) written using some human-readable computer language, usually as text. The source code of a program is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source code. The source code is often transformed by a compiler program into low-level machine code understood by the computer. The machine code might then be stored for execution at a later time. Alternatively, an interpreter can be used to analyze and perform the outcomes of the source code program directly on the fly.
Most computer applications are distributed in a form that includes executable files, but not their source code. If the source code were included, it would be useful to a user, programmer, or system administrator, who may wish to modify the program or to understand how it works.
The different types of code that are used in computer-
BCD Code: BCD (“Binary-Coded Decimal”), also called alphanumeric BCD, alphanumeric BCD, BCD Interchange Code, or BCDIC, is a family of representations of numerals, uppercase Latin letters, and some special and control characters as six-bit character codes.
Alphanumeric code: Alphanumeric (sometimes shortened to alphanumeric) is a combination of alphabetic and numeric characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection.
Merriam-Webster observes that the term “alphanumeric” may often additionally refer to other symbols, such as punctuation and mathematical symbols.
Unicode: Unicode is a computing industry standard for the consistent encoding, representation, and handling of text expressed in most of the world’s writing systems. Developed in conjunction with the Universal Character Set standard and published as The Unicode Standard, the latest version of Unicode contains a repertoire of more than 110,000 characters covering 100 scripts and multiple symbol sets.