Why do we do resolution of vectors?

Vector resolution is important when analysing motion in two or three dimensions. It's used in vector addition and subtraction, projectile motion, and expressing velocity or acceleration using component form. Resolution with unit vectors also helps in applying kinematic equations to multidimensional

Vectors can be resolved generally into any two non-parallel directions. These are done more as rectangular components using unit vectors. The latter is most common in physics and engineering to represent them into Cartesian coordinates for simplified vector operations.