First Law
A body remains at rest or in uniform motion unless acted upon by a force
This means for the particle or some body without any force, it maintains its motion in a straight line. We call it free body or free particle.
Second Law
A body acted upon by a force moves in such a manner that the time rate of change of momentum equals the force
Third Law
If two bodies exert forces on each other, these forces are equal in magnitude and opposite in direction