Add-on: something that has been or can be added to an existing object or arrangement.

Mod: A mod or modification is the alteration of the program code of a video game in order to make it operate in a manner different to its original version.

This post is for the TES single player gamers who should understand that you wont be able to find a mod workshop where you can download new swords and the likes.

the UI of the game is fully modable for LUA scripting. That means, if you have enough knowledge you can create different tools such as Damage Meters, Healing Over Time meters, tools for crafters, raiders and other useful programs.

Some ESO fans think that it will be possible to add their own items like armor or weapon using LUA but it’s misleading. (thats what mods are) Any addon for an MMO game is a tool with limited possibilities. It can modify UI or track, collect, anolyze or show information. But it does not add new objects or items into the game itself.

For example a Crafting add-on may display different advise for crafters or collect statistics about your crafting activity, but, it can’t add new types of ore or a new recipe into the game. You may only create programs that modify UI or collect, anolyze and display different data.

I feel like people saying mods/addons in a whole different context is going to screw up allot of people as in what they can achieve through the modable LUA scripting. Some know the difference, some don't. Just a small lesson to show the difference for the newbies to MMO's.

Except that what you're calling add-ons are also called UI mods, or mods for short They are modifications to the user interface, so it's a perfectly appropriate usage.

Yes, some people get confused by this, but you can't resolve it by attempting to get people to stop using the word "mod" where it fits Just have to focus on the "UI" part of it.