This is from Vattam. I was a Biology student through high school, which means I remember some things about inflorescences and foliage. This leaf, common enough, is a typical example of what’s called a doubly compound pinnate leaf. The main rib branches out into secondary ribs, which produce the pinnae.
Why leaves aren’t all uniformly shaped is an interesting question, but one that was never ever asked, discussed or hinted at in high school. I could guess, of course, that this is because a bipinnate structure might provide more area for gaseous exchange and sunlight absorption from the atmosphere, but I’d much rather know that from discussion with a teacher. High school destroyed any chance that I might have developed an interest in biology. You suck, PUC Board of Karnataka!