$[1]$ Robot Kinematics General Concept

$($a$)$ Explain the reason and advantages of introducing coordinate frames at each link in robot kinematics for a manipulator.

$($b$)$ Explain the characteristics and advantages of the $4$x$4$ homogeneous transformation matrix, along with relevant equations.

$($c$)$ For a specific robot manipulator, explain the process of solving for position in both forward and inverse kinematics, using equations and diagrams.

$($d$)$ For a specific robot manipulator, explain the process of solving for velocity in both forward and inverse kinematics, using equations and diagrams.