Comparison of Mechanism, Machine and Structure

Mechanism		Machine						Structure

1. There is relative	Relative		motion		exists		There	is	no	relative
motion between the parts	between		parts		of	a	motion		between		the
of a mechanism	machine.						members of a structure. It
							is rigid as a whole.

2. A mechanism modifies	A	machine consists				of	A structure			does	not
and transmits motion.	one or more mechanisms						transform motion.
	and	hence		transforms
	motion

3. A mechanism does not	A	machine		modifies			A structure does not do
transmit forces and does	energy or do some work						work.	It	only	transmits
not do work							forces.

4. Mechanisms are dealt	Machines		are	dealt with			Structures are dealt with
with in kinematics.	in kinetics.						in statics.