Full moon
The moment each month the Moon sits exactly opposite the Sun — the bright peak of the lunar cycle, on the far side from the new moon.
A full moon is the instant the Moon reaches the exact opposite point from the Sun, a precise 180-degree angle between the two. From Earth this is when the Moon appears fully lit, rising as the Sun sets, the visual peak of the monthly cycle. It falls roughly midway between one new moon and the next, and it's usually read as a moment of culmination — something started weeks earlier coming to a head, or becoming visible, rather than something new beginning. Like a new moon, a full moon happens at a precise instant and in a specific sign, which colors what kind of culmination the moment tends to bring. Two full moons in one calendar month is unusual but not impossible.