How do LED tube lights work?

 Yesterday my father brought LED tube light to replace with normal fluorescent tube light. 

Light Emitting Diodes ( LED) generally produces light when current runs through them

 As we know a diode has P-side and N-side. 

The N-side injects electrons to the P-side and P-side injects holes to N-side. 

Then on each side, the majority carriers reacts with these injected carriers , produces light taking the energy from electric current. 

For usual florescent tube light, we need a starter to ignite the mercury found inside and mainly used to complete the electric network. 

But for LED tube light, we don't need a starter. 

LED tube light is considered to be energy efficient. 

Shopkeeper said LED tube lights give bright light compared to florescent tube lights. I didn't feel any difference.