High can refer to the height of something (how tall it is) or it can describe it's position. However using tall is most common and natural for speaking of height. Although everyone will understand "That's a high building." it's technically not correct. You should say "That's a tall building." You can say "That building is really high into the sky." Here you wouldn't use tall because you're using high to speak of the actual position of the building in the sky.

High is usually used to deskribe an object, for example: a high building. Tall is used to describe a person, for example: He is tall.

people cannot be "high"