Camber is angle wheel makes with vertical axis. The larger the camber the greater the angle increases stability. Easier to propel. However it will increase the width of the chair. It will increase wear and tear on shoulder.
Caster is the other name for the front tire.
They don t do well on carpet. Tiny caster can get stuck like when you get off elevator. I usually prescribe caster no smaller than 4 inch. Newer chair comes with caster that s one-piece. Hand rim is the part on the outside.