That is what it symbolizes. As for what meaning people have assigned to it, that varies with cultures as it's a very universal symbol. But I took it off Phoenician scarabs (as in scarab-shaped seals) and what exactly they had in mind is lost. But I can tell you it's represented above enthroned kings and gods/goddesses.
I got my hands on some rare books and just this week my research has answered this question abotu what the horizontal crescent with the circle means exactly This crescent is actually celestial, it represents the sky, and the circle is the sun carried by the sky, i.e during the day time as opposed to rising or setting.