Newton's first law state the anything/object will remain in rest if it is in rest and will remain in motion if it is in motion until unless any external force applied or act on its. first law is also known as law of Inertia. Inertia is inability of the object to change its state of rest or of uniform motion . Inertia depends upon the mass of the object. Inertia is of three type:1.Inertia of Rest 2 . Inertia of motion 3.Inertia of direction.

Newton's First Law of Motion:
Newton's first law of motion, also known as the law of inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion with a constant velocity, unless acted upon by an external force.

Law of Inertia:
The law of inertia is a fundamental principle in physics that describes how objects behave when no external force is acting upon them. It is often referred to as Newton's first law of motion. The law of inertia states that an object will remain at rest or continue moving in a straight line at a constant velocity unless acted upon by an external force.

Explanation of Newton's First Law of Motion:
Newton's first law of motion can be explained in greater detail as follows:

1. Rest and Motion: An object at rest will remain at rest, and an object in motion will continue in motion, unless acted upon by an external force. This means that objects have a natural tendency to resist changes in their state of motion.

2. Inertia: Inertia is the property of an object that resists changes in its motion. The law of inertia states that the inertia of an object is directly proportional to its mass. Objects with greater mass have more inertia and require more force to change their state of motion.

3. Examples: Examples of the law of inertia can be observed in everyday life. For instance, when a car suddenly stops, the passengers continue moving forward due to their inertia. Similarly, when a bus takes a sharp turn, the passengers lean towards the outside due to their inertia.

4. Friction and External Forces: In the absence of external forces, an object will continue its motion indefinitely. However, most objects experience various external forces such as friction, which can slow down or stop their motion. Friction is a force that opposes the motion of objects in contact with each other.

5. Uniform Motion: If an object is moving with a constant velocity in a straight line, it will continue to do so unless acted upon by an external force. This principle is essential for understanding the motion of objects in the absence of external forces.

6. Equilibrium: When the net force acting on an object is zero, it is said to be in a state of equilibrium. In this state, the object can be either at rest or moving with a constant velocity.

In conclusion, Newton's first law of motion, or the law of inertia, explains how objects behave when no external force is acting upon them. It states that objects at rest remain at rest, and objects in motion continue moving with a constant velocity, unless acted upon by an external force. Understanding the law of inertia is crucial for comprehending the behavior of objects in various physical scenarios.