Enemy Stun Threshold meaning?

What does ... 10% reduce enemy stun threshold mean? Does it mean Enemies get's stunned more? OR I get less stunned?

I checked the Stun Gem.. It says this.. "Hits made by skills supported by this gem get a reduced stun threshold modifier, increasing the chance that they will stun the enemy."

Are the nodes that says reduce enemy stun threshold works the same thing as this gem?

All I know is that threshold means like Pain Threshold, the higher your pain threshold is, it means it would take a lot of pain for you to react or get mad or get hurt. So if a skill passive node says % reduce enemy stun threshold, does it mean that the enemy will get stunned more? If the enemy has 100% then 100 - 10.

Short answer: yes, it means you stun monsters more.

Long answer: like elemental status effects, stun is based on what percentage of a monster's life you're dealing as damage per hit. In the case of stun, the chance to stun scales with damage dealt by a single hit, scaling from no chance if you deal under 10% of the monster's life to a guaranteed stun if you deal more than 50% in one hit.

Reduced enemy stun threshold modifies the enemy life value used in the stun chance calculation, making it more likely that you will stun. Do note that it is not as straightforward as "10% reduced enemy stun threshold = 10% more stuns". See here if you want to know the details.