What does Motivation mean?

Asking "what is Motivation?" is equal to asking about happiness, satisfaction, and even sadness. It is entirely up to the individual's life experiences. Evidence of this is the fact that there are a myriad of theories, not "laws," that define motivation. As such, it remains a philosophical debate.
The Dual Factor theory by Hertzberg
This theory says that there are two ways to be motivated: One, is the basic factor of liking what you are doing, or your environment, your co-workers, and so on. Those are, what he calls, the motivating.
The second, is what he calls the hygiene factors. This entails the opposite of the motivating factors. These are the factors that, if they are not good enough, they will be "cleaned out" by the individual. Examples are: salary, benefits, policies, and people.
Maslow's Hierarchy of Needs
This theory dates back to a 1943 paper, written by Abraham Maslow. While motivation is nowhere in the hierarchy, Maslow states that, in order to do anything, one must have, a) safety, b) security, c) health. Those would be the motivating factors to exert a new action. In a way, motivators equate "needs." We need motivation first, in order to conduct an action. Motivation is everything.
Expectancy
This motivation theory relies on basic conditioning. We behave however it fits us best. The motivation is the outcome: for example, if you want to make money, then work harder. If you want to earn the trust of your boss, stay later at work and develop good listening skills in the event that he or she needs to make a friend.
The three factors of motivation in this theory are: expectancy, instrumentality, and valence. In the example given above, the expectancy would be the trust of your boss. The instrumentality would be you, staying later at work to seize the chance to be a sounding board to your boss if he or she needs support. The valence is the end-result: to earn their trust.
As there are other theories (check links included), you will find that the main factors are that a) we need to be of sound of mind and body, b) we need to have a goal in mind, and c) we need to have a way to get it. That is, basically, what motivation means.
http://www.analytictech.com/mb021/motivation.htm

https://lingtechguistics.com/2015/02/05/motivation-and-learning-theories-for-sla-through-chomsky-bandura-vygotsky-krashen-and-gardner/