In
computers, a dynamic link library (DLL) is a collection
of small programs, any of which can be called when needed
by a larger program that is running in the computer. The
small program that lets the larger program communicate with
a specific device such as a printer or scanner is often
packaged as a DLL program (usually referred to as a DLL
file). DLL files that support specific device operation
are known as device drivers.
The advantage of DLL files is that, because they don't get
loaded into random access memory (RAM) together with the
main program, space is saved in RAM. When and if a DLL file
is needed, then it is loaded and run. For example, as long
as a user of Microsoft Word is editing a document, the printer
DLL file does not need to be loaded into RAM. If the user
decides to print the document, then the Word application
causes the printer DLL file to be loaded and run.
A
DLL file is often given a ".dll" file name suffix.
DLL files are dynamically linked with the program that uses
them during program execution rather than being compiler
with the main program. The set of such files (or the DLL)
is somewhat comparable to the library routines provided
with programming languages such as C and C++. |
