LCD Display:
An LCD is short for Liquid Crystal Display. It is basically a display unit which uses liquid crystals to produce a visible image.
When current is applied to this special kind of crystal, it turns opaque blocking the backlight that lives behind the screen. As a result that particular area will become dark compared to other. And that’s how characters are displayed on the screen.
16×2 LCD Display:
These LCDs are ideal for displaying text/characters only, hence the name ‘Character LCD’. The display has an LED backlight and can display 32 ASCII characters in two rows with 16 characters on each row.
f you look closely, you can actually see the little rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.
Although they display only text, they do come in many sizes and colors: for example, 16×1, 16×4, 20×4, with white text on blue background, with black text on green and many more.
The good news is that all of these displays are ‘swappable’ – if you build your project with one you can just unplug it and use another size/color LCD of your choice. Your code may have to adjust to the larger size but at least the wiring is the same!