Metacognitive strategies: the word "meta" suggests that the strategy refers to thinking about the learning process itself - it's learning about strategies via actively thinking about them, e.g., planning, monitoring, self-evaluation, etc.
Cognitive strategies refer to what a teacher can do to make the learning process more efficient and effective, e.g., manipulating certain tasks, changing the pre-established order to task presentation or in any other way enhancing cognitive processes of a learner (memory, information retention, attention, categorisation)
Social/affective strategies: using social interactions as a way of acquiring knowledge (face-to-face interactions, situation simulations); evoking certain emotions during the learning process (engaging students in emotionally-charged topics)
