See Aristotle on Causality:
Each Aristotelian science consists in the causal investigation of a specific department of reality. If successful, such an investigation results in causal knowledge; that is, knowledge of the relevant or appropriate causes. The emphasis on the concept of cause explains why Aristotle developed a theory of causality which is commonly known as the doctrine of the four causes. For Aristotle, a firm grasp of what a cause is, and how many kinds of causes there are, is essential for a successful investigation of the world around us.
Causes "act" producing effects: changes.
There are four types of causes:
It is clear then that there are causes, and that the number of them is what
we have stated. The number is the same as that of the things comprehended under
the question ‘why’. The ‘why’ is referred ultimately either, in things which do not involve motion, e.g. in mathematics, to the ‘what’ (to the definition of straight line or commensurable or the like); or to what initiated a motion, e.g. ‘why did they go to war?—because there had been a raid’; or we are inquiring ‘for the sake of what?’—’that they may rule’; or in the case of things that come into being, we are looking for the matter. The causes, therefore, are these and so many in number.
Now, the causes being four, it is the business of the student of nature to know about them all, and if he refers his problems back to all of them, he will assign the ‘why’ in the way proper to his science—the matter, the form, the mover, that for the sake of which. [...] The question ‘why’, then, is answered by reference to the matter, to the form, and to the primary moving cause.
We must explain then first why nature belongs to the class of causes which act for the sake of something.
We can consider the paradigmatic example of the statue:
The material cause: the bronze of a statue.
The formal cause: “the form”, the shape of a statue.
The efficient cause: “the primary source of the change or rest”, e.g., the artisan, the art of bronze-casting the statue.
The final cause: “the end, that for the sake of which a thing is done”.
Thus, the efficient cause: the artisan, acts (i.e.produce) the statue, using the broze (the material cause) and shaping it [the formal cause] in order to manufacture the statue "for the sake of an end" : the final cause.