NPCs generally do not level at all with the character. This means that you can (and will!) encounter NPCs that are 20 levels above you that you aren't meant to fight quite yet, but they will not get stronger as you do.

Do you level up in Morrowind?

How do I level up in Morrowind and Oblivion? In order for your Morrowind character to increase in levels, your character must increase in a Major or Minor skill 10 times. This can be any combination of Major and Minor skills, so long as they have been increased a total of ten times.

Does Elder Scrolls Online have level scaling?

All content in Elder Scrolls Online now scales with the player: quests, monsters, world bosses, and rewards. If a monster is meant to be difficult, that difficulty is largely fixed. ... The magical part of the level scaling mechanic is it means players can jump right into Morrowind from the beginning.