There’s no real difference between LED and WLED displays; in other words, it’s just a marketing gimmick. LED stands for Light Emitting Diode, whereas WLED means White Light Emitting Diode.
LCD: LED vs. CCFL
Note that LED is not the same as LCD (Liquid Crystal Display).
The difference between the two of them is the backlight — they are technically both LCDs since a LED display uses a liquid crystal display.
LCDs have two polarized glass layers. These liquid crystals then proceed to block or pass the light to the display based on the picture.
However, the crystals do not produce any light whatsoever; the light comes from a series of lamps at the display’s backside — the backlight.
Now, on an LCD, where there is no mention of ‘LED’ anywhere, these lamps are fluorescent lamps (CCFL LCD).
On the other hand, on an LED display, these lights in the backlight are Light Emitting Diodes (LED).
LED TVs and monitors use less power, can be lighter and thinner, and can have a better image quality than CCFL LCD TVs and monitors.
Nowadays, almost all modern LCDs utilize LED backlighting.
There are also OLED displays that don’t have a backlight but produce their own light, which allows them to create superior image quality with an infinite contrast ratio.
LCDs also have different panels, including IPS, TN and VA, which you can learn more about here.