I often hear nanas and jhanas mentioned together as if they are different but related concepts. Is that true are they different or is nanas the exact equivalent of jhanas? Are the different terms used in different traditions perhaps?
They are different things. Jhana refers to a particular kind of concentrated state of mind, and the word nana simply means knowledge, but in a meditative context, it refers to one of the 16 stages of knowledge which are described in part III of the Visuddhimagga.