The expressive metaconcept of form has multiple levels of meaning in Aristotle. A theme common to these various senses is that depending on the context, form is a way of being, or a way of being and doing.
A way of being and doing can be understood as constituted by a counterfactually robust effective orientation with respect to ends. The ends in question may belong either to whatever is considered as “having” the form, or to an intelligence that discerns the form, but in either case, the effective orientation that is form is attributed to the “thing” that “has” the form.
Thinking in terms of form is thinking in terms of a sort of primarily adverbial, richly modal, differential-consequential pragmatic determination rather than in terms of objects and extensional identity. That mouthful notwithstanding, it is often actually simpler than life in the kingdom of nouns.
Then there is a hylomorphic biological one where psyche or “soul” is said to be the “form” or first actuality of the body, which seems to include its capacity for nutrition and self-movement and what we might call its elemental desire.
Things having to do with second nature or second actuality, such as character or intellect in a human, constitute a further level grounded in sociality and language.
Yet another is associated with the complete actualization of a thing, which includes not only actuality but its interweaving with material contingency and structured potentiality. It is at this level that we can speak of form as a counterfactually robust effective orientation in some delimited context, fusing potentiality and actuality together.
The complex functional role of form in Aristotle has a relatively close analogue in the role of mediation in Hegel. (See also