What is the difference between inertia and acceleration?

Inertia and acceleration both relate to Newton's laws. Acceleration is mentioned in his second law. This law states that acceleration is directly proportional to force and inversely proportional to mass. Inertia on the other hand, is the subject of Newton's first law. It states that an object at rest will remain at rest until acted upon by an unbalanced force. In the same manner, and object in motion will remain in motion until acted upon by an unbalanced force. A definition of acceleration: The increase of velocity over a certain time span, usually written as meters/second^2. A definition of inertia: The desire of an object to remain at a constant velocity, or the resistance to acceleration.