What is a Pixel or a Strip
LED Pixel / LED Strip / LED String
Two terms used all the time but mean many things to different people and cause likely the most confusion to even experienced people.
Let's see if we can clear some of the air on this page.
This is a single Light Emitting Diode, can be any colour or multiple colours. A single colour LED will usually have two connections with multiple colours having more connections with often two connections per colour, though the common 5mm or 8mm RGB LED will have 4 connections, one common and three colours.
Here's a "5050" package LED (5.0mm x 5.0mm) with 3 "dies". Each die can be the same or a different colour. Most RGB LED strip uses RGB 5050 LEDs.
Here's a "3528" package LED (3.5mm x 2.8mm) with 3 "dies". Each die can be the same or a different colour.
Here's a 8mm package LED with 3 "dies". Most RGB LED pixels uses RGB 8mm LEDs.
These can be flexible or solid strip with multiple LED's. A solid strip will usually be sold as a fixed size. Flexible strip is usually available by the metre (3 foot) and often comes as a 5M Roll. Flexible strip is commonly available with 30 LEDs per Metre with higher counts like 60 LED's per Metre becoming more common. Like a single LED these are available in any available LED colour including RGB LEDs.
A string of LED's has each LED joined to the next with copper wire. Strings are best known as normal LED christmas lights and can include icicle lights. Like strips, Srings can be made from any colour LED and are normally a single colour. Multi-coloured strings just have different coloured LEDs. RGB Strings are available and consist of 4 connection RGB LEDs all connected in parallel.
The Strip and Strings above can be referred to as non-intelligent LED lighting as individual LED's or even groups of LED's cannot be controlled seperately.