Niebla literally translates to "fog" or "mist". It's a wonderfully atmospheric word that you don't hear in songs every day.
In this beautiful ballad, the line "Se aclaró aquella niebla" ("That fog cleared up") is used as a powerful metaphor. It represents the moment the character's long-held confusion and uncertainty finally vanish, replaced by the clarity of seeing the truth for the first time.
This beautiful duet is from the Disney movie Tangled, and it's all about two people finding clarity and a new life in each other. Before they meet, both singers feel like they were living in a fog. One says, "Tiempo que no me imaginaba lo que me perdí" [A time when I couldn't imagine what I was missing], suggesting a life spent looking out from a distance, unaware of what was possible. The other was lost in their own way, "persiguiendo un sueño... en la oscuridad" [chasing a dream... in the dark].
Everything changes when they find each other. Suddenly, "todo es claridad" [everything is clear] and the fog lifts. They realize that the other person is the source of this amazing new feeling. The song's title and most important line says it all: "Veo en ti la luz" [I see the light in you]. It's a sweet and powerful declaration that finding the right person can completely change your world, making the sky seem bluer and your path finally clear.