Short answer. Continuous easements work on their own, without a person having to act each time; discontinuous ones need a human act every time they are used. Apparent easements show visible, external signs of their existence; non-apparent ones show none. Article 615 of the Civil Code sets out both distinctions, and they can combine in any pairing.
What the law says
Continuous easements are those the use of which is or may be incessant, without the intervention of any act of man. Discontinuous easements are those which are used at intervals and depend upon the acts of man.
Civil Code, Article 615 — Continuous, Discontinuous, Apparent, Non-Apparent. Read the full provision →
Continuous vs. discontinuous: does a person have to act?
Article 615 defines continuous easements as those the use of which is or may be incessant, without the intervention of any act of man, and discontinuous easements as those which are used at intervals and depend upon the acts of man. A drainage easement that lets water flow through a neighbor's land on its own operates continuously; an easement of right of way, which is only used when someone actually walks or drives across it, is discontinuous because each use requires a human act.
Apparent vs. non-apparent: is it visible?
The same article defines apparent easements as those which are made known and are continually kept in view by external signs that reveal the use and enjoyment of the same, and nonapparent easements as those which show no external indication of their existence. A visible path, a drainage pipe, or a window opening onto a neighbor's lot signals an apparent easement; an easement with no outward physical trace, such as a restriction not marked on the ground, is non-apparent.
The two distinctions are independent of each other
These are two separate axes, not one sliding scale, so an easement can fall into any combination: a visible drainage system is both continuous and apparent, while an underground pipe with no visible trace can be continuous yet non-apparent. A right of way marked by a worn path is discontinuous yet apparent, because it needs a person to walk it even though the path itself is visible. The classification depends on the specific physical facts of each easement.
Why the classification matters
This article defines the categories; other Civil Code provisions attach different consequences to each classification, particularly around how an easement may be acquired or established. Because the practical effect of being continuous, discontinuous, apparent, or non-apparent depends on those other rules being applied to your specific easement, it is worth having a lawyer confirm the classification before relying on it for anything more than description.