LED PL Bulbs are replcements for Compact Fluorescent PL Bulbs. PL is an acronym for Plug In lamp, and these lights have special bases. Behind the scenes, compact fluorescent bulbs also have a ballast that is used to drive the lights.
Here is a list of bases that make up the family of PL Bulbs
The most common bases are G23 and G24 bases, G23 GX23, GX24 and G24.
Why Convert from Compact Fluorescent to LED Bulb G23 and G24 Lights?
Converting to E26 Base
My LED Lighting Guide offers base conversions from PL Base to E26. This allows you to convert over to more traditional style bulbs, like PAR or BR style bulbs,