In
computer programming, an
entry point is where control is transferred from the
operating system to a
computer program, at which place the processor enters a program or a
code fragment and
execution begins. In some operating systems or
programming languages, the initial entry is not part of the program but of the
runtime library, in which case the runtime library initializes the program and then the runtime library enters the program. In other cases, the program may call the runtime library before doing anything when it is entered for the first time, and, after the runtime library returns, the actual code of the program begins to execute. This marks the transition from
load time (and dynamic
link time, if present) to
run time.