Runtime refers to events that occur while a program is executing (running). Runtime programming enables the logical occurrence of such events during the execution of an application, without having to go through time-consuming and error-prone cycles of the compilation of code and the execution of the compiled code.

When a program is executed, space is made available and the main function of the program is copied into memory as a sequence of executable statements. The space is called the runtime stack. At first the runtime stack is empty. But, as a particular function is called during program loading, the called function is also copied into the stack. The stack fills up with copies of required functions. Runtime creates virtual processors--virtual mini-processing units. These schedule the order of execution of the copied functions. As each function is executed, the copy of that function that was made is removed from...