When I first started meditation, I simply followed whatever the guided meditation, book, or instruction I had in front of me.
I had no idea there were different types and categories of meditation, and that they differ significantly in their approach.
If you are working within a tradition – these distinctions and categories may be irrelevant. Learn from a legitimate teaching source completely, and just do it.
But many in the West are cobbling together and learning on their own, and may be conflating two common meditation techniques: concentration (or Samatha) and mindfulness (or insight).