Jewish rituals and ceremonies, like mitzvos (commandments,) are divided into three major categories; eidus (testimonies,) chukim (decrees) and mishpatim (judgements.)
Eidus are laws that testify to an historical event or a religious belief. For example Pesach (Passover) is a testimony to the fact that Hashem (God) miraculously took us out of Mitzrayim (Egypt,) Shabbos is a testimony that Hashem created and runs the world and Bris Mila (religious circumcision) is a testimony of Hashem’s covenant with Avraham.
Chukim are laws that are commanded by Hashem which do not have a simple interpretation or rational. They are done exclusively because Hashem commanded them. For example the laws of kashrus (kosher food,) taharas hamishpacha (family purity) and the ultimate chok, the parah aduma (red hefer) the ashes of which are paramount for ritual purification of anyone who came in contact with a dead body and contracted tumos meis (spiritual impurity from the dead.)
Mishpatim are laws that have solid societal rational, so much so that most societies practice some or all of them. For example not to murder, not to steal and not to damage people or property.
When we look at the Asesres Hadibros (the Ten Sayings mistranslated as commandments) we find that the first three, Belief in Hashem and submission to His will, not to worship other gods and not to use Hashems name in vain are chukim
Shabbos, as stated above is an aidus.
Not to murder, not to steal, not to commit adultery, not to bear false witness and not to covet (which is only transgressed when steps are taken to acquire the desired article – Rambam Hilchos Gezeilah ch.1: h:9,) are mishpatim; so much so, that they are integral to the legal codes of most modern countries.
Kibud av vaem (honouring ones father and mother) is mostly chok but has a level of mishpat associated with it.
All Torah rituals and ceremonies can be categorised in the same way. There are some that are practiced purely because Hashem commanded, some that relate to an historical event and some that are clearly for the good of society.
The three chagim (Pesach, Shavuos and Sukkos) are clearly eidus which testify to Hashem’s bringing us out of Egypt, giving us the Torah and sustaining us in the desert for forty years.
Wearing tefillin, saying the Shema twice a day and having mezuzos on our doors are chukim that relate to our recognition of Hashem as the master of the Universe and our lives.
Finally returning a lost article, helping a person lift his animal’s load that has fallen and not saying loshon hara (slander) are clearly rituals that relate to mishpatim.
So we see that all ceremonies and rituals, like all mitzvos in general, can be categorised according to these three categories.