What exactly (more exactly) do you do in the CIA's NCS (internship)?

there extremely competitive first you need a federally issued "security clearance" then you have to put in maximum effort and also you gotto work for free as in unpaid otherwise they will easily find somebody else as far as after the internship goes thats probably all there is internship cause in the first place uncle sam is running out of money and no they wont print money to fund your employment but if your willing to work for free as in no money i could imagine you becoming a senior operative within the you know what ; ) which only a few people know where

It all depends on which area you are interning in.

There's a reason the description is "painfully vague", though a lot of it is just regular intern stuff-- you know, basic administrative/clerical work. You'll learn more as you advance through the application process, though bear in mind that these internships are extremely competitive.

I pretty definite its nothing cool on account that you usually need unique security clearances. You likely will do stuff nobody else wishes to do like constructing spreadsheets or compiling notes and data from one-of-a-kind places like whiteboards and scribbles.