There are lots of different definitions for women's apparel.
For me, leggings have no feet. They can be of heavier or lighter weights and can be either patterned or solid colored.
Tights, once again for me, are typically footed and lighter weight than leggings and in the extreme would resemble an opaque panty hose.
We live in Colorado and we both wear either leggings or tights under our skirts or dresses, whether with shoes or boots (but preferably boots) all winter.
As for pants, I only wear them when I am riding my Harley.
When you get to my age you get to choose what you want to wear for your own comfort and style,
Enjoy,
Tia Anne