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.