* The `#include <stdio.h>` is a preprocessor command. This command tells compiler to include the contents of `stdio.h` (standard input and output) file in the program.
* The `stdio.h` file contains functions such as `scanf()` and `printf()` to take input and display output respectively.
* If you use `printf()` function without writing `#include <stdio.h>`, the program will not be compiled.
* The execution of a C program starts from the `main()` function.
* The `printf()` is a library function to send formatted output to the screen. In this program, the `printf()` displays `Hello World!` text on the screen.
* The `\n` in `printf` creates a new line for the forthcoming text.
* The `return 0;` statement is the "Exit status" of the program. In simple terms, program ends with this statement
* Conventionally, the first ever program you write is the "hello world" program, be it in any language.
* This is because Brian Kernighan was the first to write "hello, world" program for the documentation of the BCPL programming language developed by Martin Richards.