What is called vector math in Blender is, in most cases just math performed on three elements at the same time.
Multiplying two vectors is just multiplying the first elements of the two vectors which gives the first element of the result vector, etc…
This makes use of so-called SIMD instructions (Single Instruction Multiple Data) in (Assembly) programming; there are some extra large special Registers in you computer (think something like 256 bits, in stead of the usual 64 bit (or 32 bit if it’s really old)) that have been around since 1999 (I think…).), that can add (or multiply, or…) the elements of two lists simultaneously! This guy explains things really well: https://www.youtube.com/watch?v=QghC6G8TyQ0
Like I said, most of those Vector Math operations are just simultaneously performing that operation on the elements of the vector…
The rest is self explanatory (Length,….),look at the thumbnails,they usually say something like entry-wise…
The exceptions are Dot Product and Cross Product that are actual vector math and need tobe understood. And Reflect and Project, which are again self-explanatory (thumbnails!).
TLDR: learn about dot and cross product and you’re good to go 😉
