The Home Screen is usually the screen you see when you turn on your calculator. The Calculator's user uses this screen to type in equations for the calculator to solve.
In addition, the TI-84 uses this screen as the IO Screen.
The home screen of the TI-84 uses the big character's map. Every character is 7 pixels high and 5 pixels wide. Between two characters, there is a 1 pixel wide horizontal line. Because the display is 96 pixels wide, you can display 16 character's on one single line.
If you use one of the newest operating systems, and have set Mathprint in the MODE-menu on, you will have 2 pixels between every line, meaning that only 7 lines can be displayed at once. If you, however, do not have OS 2.53 or 2.55, or you have stuck to the classical view, only 1 pixel is left between every line. Therefore, you can have 8 lines of calculations on the home screen.
Other screens in the TI-84 include the Graph/Drawscreen, and the tablescreen.