Basic C++ I/O

cin - common input, same as System.in in Java and stdin (standard input) in C. Typically refers to the keyboard.
This statement represents the flow of data from the keyboard into the object x:
```
    cin >> x; 
```
This symbol is used to get input and is called extraction:
```
    >>
```
cout - common output, same as System.out in Java and stdout (standard output) in C. Typically refers to the display screen.
This statement represents the flow of data from the the object x to the computer screen:
```
    cout << x; 
```
This symbol is used to create output and is called insertion:
```
    <<
```
endl - end line. Used to print a newline.
```
    cout << "Hello World." << endl;
```