First Program in C++

Line 1: #include is preprocessor directive it an instruction to preprocessor to add header file in the program. Preprocessor is a part of compiler that is why it is some time called compiler directive. Preprocessor modify the code before compilation.

Line 3: Namespace is a collection of classes, objects and variables. Namespaces are used to resolve the naming collisions. In upcoming videos it will be discussed a lot.

Line 5: Main function is defined, It is a place where the execution of C program start. int is return type of main function and main take no parameter that is why empty parenthesis are used.

Line 6-9: called program body. There are two instruction in body of main first is cout and second return. cout is output object which output on the screen console. Program return 0 if it execute successfully.

for more detail visit: https://www.youtube.com/watch?v=KjgDViojR9Y