A library is a collection of routines, procedures, program parts or programs
which are frequently used and which are combined in a library file. The individual routines and procedures can be retrieved from the library by the programmer and used for program creation
. Adistinction is made between resident libraries, which are available at all times during operation, transient
libraries, whichmust first be loaded from a storage medium, and dynamic link
libraries(DLL), dynamic reference lists whose functions are only loaded dynamically when a
Libraries are part of the development environment of a programming language and shorten the programming time. Libraries with online searches are electronic libraries, e-libraries.