Staggered or collocated grid?

[AbsoluteNoober]

Thank you for this wonderful stuff, professor.

Are the discretization grids used in the cavity flow simulation staggered or collocated ones? From the indexing of the prime variables u, v, p it looks like the collocated grid. But the use of fractional step integrating and pressure correction means staggered gridding...? As a newbie, I am confused.