Preprocessor Directive: This section includes a preprocessor,which can be represented by #include and a header file,this is invoked by the compiler before compilation.
Main Function: This is Section is most important section as the program cannot operate without a main funtion.
Expression Statement: This Statement are used to elobrate ,express and specify the operation in words.
Declaration Statement: This Statement are used intialize a variable and assign it some value.
Return Statement: This Statement is used return some integer value if the main has some return type such int etc, void function cannot return value.