There are two types of LED backlights (in simple terms), edge-lit and direct.
EDGE LIT
In an edge-lit backlight, there is a row of LED light emitters (usually white) along one, two, or three edges of a backlight with reflective films and coatings to funnel that light across the entire back of an LCD panel in a uniform manner.
Advantages:
Results in a thin overall LCD display profile. If you see a panel that is very, very thin, most likely it is using an edge-lit backlight design.
It is lower cost since it uses less LEDs to cover a larger area of display.
Disadvantages:
Can have some brightness uniformity issues, creating bright edges of More…