Orochimaru's Juinjutsu technique are the cursed seals that were an often-used technique of Orochimaru in the series.
Orochimaru usually gave his cursed seal to his most powerful and unique followers and guinea pigs to either make them his strongest warriors or to prepare them to become a potential host bodies in the future or simply as test subjects. To apply a cursed seal, Orochimaru usually bites his intended target. As he had sharp fangs and an extendible neck, this was a relatively simple task. The seal then appeared on the body of the victim near the puncture wound, which would cause them to subsequently lose consciousness. The design of the seals could either vary from person-to-person or was dependent on the type of seal Orochimaru chose to brand the victim with. If the victim had survived the application of the seal, they would awaken with the first level of the seal activated and enraged due to the seal's influence.
Orochimaru originally developed the cursed seals through experimentation on Jūgo, whose body naturally produces an enzyme that triggers bodily transformations, on which the cursed seal is based. Like in Jūgo and his clan members, the unrefined enzyme, extracted from him produces rage and madness in those exposed to it, while the cursed seal does not have such deficiency. Similarly, Jūgo is not limited to a single transformation, and can change the advantages of his form to fit the situation. It should also be noted that anyone who survives the application of the cursed seal is "compatible" with Jūgo. This was shown when he was able to transplant some of his flesh to Sasuke.
The cursed seals that are partially made from Orochimaru's chakra, also contain parts of his consciousness, and thus allows him to be revived when combined with a piece of his DNA to utilise the Evil Releasing Method on a host like Anko Mitarashi, Orochimaru can be resurrected completely even if his original body and self were destroyed.
For the anime-exclusive seals, they tend to have fatal side effects if handled improperly, as seen when Mizuki's seal, which is unique in that it requires extra procedures to activate its powers, he nearly died due to using it earlier than he should, and lost all his powers regardless. The ones administrated onto Team Guren would kill them if they do not take the required medication periodically, which prevents them from escaping Orochimaru's clutches.
