That makes sense. лёгкий means either "light" or "easy" depending on context. After all, what would an "easy car" be?
On the other hand, a task can be "easy" because it is "light" (in the sense of slight, minimal, not requiring a lot of effort to accomplish), so there can be a firm distinction, but not always.
Often, when the "easy" thing is a task which is stated in verb form, then "easy" acts more like an adverb, and the adverb легко is probably more appropriate.
Note on spelling: ё is used in all declensions of the long-form adjective лёгкий (e.g., лёгкая) and in the masculine short-form adjective лёгок, but in the adverb легко and other short-form adjectives (легка/легко/легки), е is used instead of ё.
The comparative adjectiвe is легче.