Ceremonies are occasions that are extremely formal and consist of a series of actions performed in a structured manor.
Ceremonial Magick is much different from your basic ritual, as rituals aren’t as formal in nature and is an amalgamation older occult teachings. One would consider ceremonial rituals to be an extension of ritual magick.
For example a ritual magick may consist of simply meditating and lighting a candle with intent. Rituals is more often considered something that is a dedicated part of a practice and more nature based.
A ceremonial ritual requires more in-depth planning, which would entail timing, a system of magick, the right tools and a dedicated space. Ceremonial Magick is considered, “High Magick” and usually involves the evoking of spirits or invocation.
Heinrich Cornelius Agrippa (1486-1535) was believed to be where this term ceremonial magic derived from. A German polymath who was renowned for his written occult philosophy written works published in 1533. Check out his written works, Three Books of Occult Philosophy.
Ceremonial Rites are more for rites of passage or achievement of the next phase or level of a path. For example, some kind of baptism, school graduation or rites to eldership.