It can by tricky
I include ceremonial magicians on this site for two reasons. The first is that Wicca has origins in ceremonial magic groups such as the Golden Dawn. The second (and, honestly, the more driving) is that too many Pagans have gotten sloppy in the definitions of magical tradition. Witches are not merely practitioners of magic. They practice particular forms of magic. The practices of witches is incredibly varied and, thus, difficult to concretely define, but all practitioners of magic are certainly not witches. Magicians often take considerable offense when someone calls them witches. They also generally do not identify themselves as Pagan unless they happen to also have Pagan religious beliefs.
Ceremonial magic is generally highly complex, and its workings can be quite lengthy. It focuses heavily on correspondences and in correct performance of ritual. Historically, what we now call ceremonial magicians frequently practiced astrology, numerology, and alchemy. Today’s culture generally defines these things as psuedo-sciences, as they fly in the face of conventional science, but they nevertheless involved rather scientific pursuits, and they required a great deal of study, patience, and education. Moreover, they were rooted in the understandings of the universe at the time. Magicians often enjoyed high positions in royal courts.
Ceremonial magic was (and is) a magical practice, not a religion, although it can certainly bear religious influences. The magicians of Europe considered themselves Christians, or else they followed something that evolved out of Christianity and which the individual magician felt was beyond and/or superior to Christianity. Basically it was Christianity without whatever “errors” the individual magician felt the less-informed masses had picked up over the centuries. Some of the great Renaissance magicians were actually priests, monks, or abbots.
High Magic and Low Magic
Ceremonial magic is frequently referred to as “high magic,” although the terms are not actually synonymous. High magic is magic which has the ultimate purpose of bringing the magician closer with the divine. Historically, this is what ceremonial magicians claimed to be doing, in comparison with “low magic,” which had mere practical purposes, was often considered to be rooted in superstition, and was sometimes equated with witchcraft.
Some modern witches do work purely practical magic. Many, however, work their magic in a very religious context and view their magic as drawing upon some connection with the divine.