Is there a difference between the two?
The following might seem only a semantic issue, but I find it rather important. For most people ritual and ceremony may seem synonyms. Their arguing is that ritual holds ceremony and vice versa. But to me this seems not the case.
A ritual may be described as a preset form of actions and words, or one of these alone, that accompany all kinds public and private outings. Lawyers are experts in ritual. The Law itself is ritualistic, but is not ceremony.
Ritual primes the human mind for something different, and this is ceremony. Ceremony is of another level than the form of actions and words. In ceremony these are transcended in a way that is in expressable in words. This makes it difficult to explain, but I will try with some examples.
In a public ceremony, like Armistice Day (England) or July 4th (USA), or in Quatorze Juillet (France) there is a setting that is comparable, but the heart of it is not the setting or the parades, or the music, but the personal realisation that we here and now have freedom thanks to those who died somewhere in the past.
In a religious ceremony like the roman-catholic Eucharist, there is the setting and the words, but the ceremony is the common man and woman whom are given a wafer by the priest with the words: this is my body. And then, identifying with Christ, he and she participate in the mind of Christ. That is the real ceremony.
In a shamanic ceremony like a despacho* there is also the setting and the words, but the heart is the intention that is laid in the despacho by the shaman and his client, and that in a fire ceremony gets conversed into the new energy that the client needs.
In all those cases it is not the ritual that counts. Rituals can be rather loose, but it is the heart of it, the ceremony that not depends on the proper execution of the ritual, but that solely depends on the frame of mind of the individual person that is involved in the ceremony.

What does this mean? It is my opinion that proper execution of rituals and the emphasis that is laid on it is a waste of time and energy. The ritual is meant to direct the mind to the ceremony, no less, but certainly not more. An excess of ritual may even kill the ceremony. But too little of it is detrimental too.
This means that Zhabkar’s text should be studied and experienced with as little ritual as possible. For some meditation that is drum driven is a perfect means to focus, for others it is not. So find your own way. But what always should be remembered is that without the proper intention, with honesty towards oneself and others, no ceremony can successfully be performed.

• a despacho is an offering of natural substances that is created purposefully by the shaman as a representation of the question at hand, and its wished for solution. The despacho is ceremonially burned and the energy that is freed by that is given back to the client.