=> #include is used to import someone else’s code in our project and we are importing or including the iostream header file
=> int main() is a function which acts like an entry point of our program. This is where the program should start executing and there should be only 1 main function otherwise an error or exception is thrown
=> expression statements are expression with semi-colan ‘;’ at the end of the line.
=> Declaration statements are statements that are used to declare something.
=> return statement is used to return the value of the method and the type of the value must match with the return type of the method.