Preprocessors are the Source of our Program those are Executed whey they are passing to Compiler and Preprocessors are always executed at the Time of Compilations. Preprocessors provide many features called Preprocessor directives and Each Preprocessor is declared with # symbol and This Directive must be written before a main program.

As we know that the Language which is used by a Algorithms is not Specific , means there is no Language which is used by a Algorithm .

We know that a computer can understand only Machine Language But the Program Written by a user is in the Form of English Language So it very necessary to convert the human Language into the Machine Language. So for this purpose we use Compiler which Converts human code into the machine code.

The Memory is allocated in two ways either in Static and either in Dynamic. In Static Memory Allocation the Size of Memory may be Fixed and pre-defined but the Limitation of Static Memory is that when a user Stores Large Amount of data or Large Number of Elements are Increased instead the Declarable size of Numbers So The Concept of Dynamic Memory Allocation is used When we doesn’t know about the actual size or when we doesn’t known about the Number of elements For this purpose we uses Dynamic Memory Allocation.