The source code, source code, program code or source code of a program or a software component describes the program flow in the syntax of the respective programming language. It records how the program behaves towards the user or other programs, what data can be entered, how this is processed and finally output again.
The source code is written by a programmer by hand, an integrated development environment( IDE) or with the help of a code generator after the special program rules mostly in ASCII and seized in an editor. The relevant commands of the programming language go into this programming, as well as certain algorithms. Source code parts, which are very extensive and contain only simple logic, are not written by hand, but are generated automatically according to templates and input parameters. This is called generative programming.
Database descriptions or UML diagrams(Unified Modeling Language), for example, can serve as templates. The finished source code is executed by an interpreter or translated by compilers into executable programs. With the interpretable programming languages no compilation is needed, since the source texts can be executed directly.