Technique
In Ars Magica, which is mostly about magic, Technique almost exclusively refers to Techniques in the context of Hermetic Arts.
A Technique is a method applied to a Hermetic Form. It more or less describes an action, whereas Forms determine the object or subject the Technique applies to. The combination of both is required to create a Hermetic magical effect.
The nomenclature used to describe Techniques is Latin verbs in the first person singular form, all of which end in "-o" to represent that grammatical form. Unlike in Latin, where the predicate or verb concludes a linguistic expression, Techniques _usually_ precede the corresponding Form to describe the Form-Technique combination.
There are 5 different Techniques: