A total solar eclipse happens when the Moon completely blocks the Sun from the person viewing on Earth because they are exactly aligned.
A partial solar eclipse happens when the Sun, Moon, and Earth are not exactly lined up. Only part of the Sun is blocked from a person looking at it from Earth
An annular solar eclipse happens when the Sun, Moon, and Earth are lined up, but the Moon is at its farthest point from the Earth. A person looking at it from Earth will the Sun blocked by the Moon but will still be able to see a bright ring of the Sun.