Monorepo support confusion

[AlwaysNoobCoder]

Hello, I am a java developer. I just started to learn web dev with vue3 + vite.

despite my java background, I have some confusion about monorepo:

for example:

/MonoRepo
     /packages
        /A
        /B
        /C

Question 1:
if B depends on A, do I need to build and reinstall A every time A was changed, to let B see the newest updates of A ?

Question 2:
if B depends on A, and C depends on B, for C, A is a transitive dependency(in java world), can the pnpm or underlying npm handle this automatically ?