Yes, there is a difference. Its the difference between selling and supporting.
Influence is motivating someone to change their beliefs and their emotional attachment
to something without their permission. Influence, in its essence, is quite wrong unless the
belief that is being transmitted is truly something the person will suffer without.
Motivation is taking someone who, through internal factors has come not to believe in
what they used to without their direct conscious decision, and giving them reason to
revert back to their old belief.
An example. Lets say I am a recruiter.
If I influence someone, I am taking someone who showed no interest in the military
before and changing their belief system through motivational techniques to want to join.
As a result, the person does something that they don’t really want to do. In this case, it is
extreme, but it could be as small as buying an ice cream cone.
If I motivate someone, I find someone who is sad, hopeless, or has enough interest in the
concept to believe that their lack of want is only a lapse due to emotional influence of
environmental factors and motivate them. In this case, I use motivational strategies to
give them a reason to believe stronger in what they want.
In another way, influence is building a house. Motivation is maintaining it. Everyone
needs to maintain their house. Not everybody needs to build a house.