Karma is both an action and the consequence of that action. It is in fact a culmination of past actions, choices and memories merging together with current desires.
Every thought you have — as a direct result of your attention and intention — leads to a set of choices. Those choices you make have a direct impact on your life. As such, your life as you know it today is a direct result of the choices you have made over a lifetime.
Now of course, every thought you have leads to specific actions, and these actions create experiences that create a set of memories. These memories leave a lasting imprint on your inner mind through the formation of neural pathways. These neural pathways build your belief systems and your belief systems influence your expectations, which likewise affect the choices you make. Karma is therefore in many ways tied to how you have programmed your nervous system over a lifetime.
You behave the way you do and you subsequently always get what you deserve (not what you want) because of pre-programmed patterns that have been integrated into your psyche.
Now this all of course happens on a physical level. However, karma might very well be even more deeply ingrained into the fabric of our being through spiritual energy on a metaphysical level.
Karma is linked to the universal Law of Cause and Effect in that every action generates a force of energy that returns to us in kind, which of course impacts us on an individual level as well as on a global level.
Individually we make choices and as a human species we also make choices. Each of those choices lead to a set of consequences to us as individuals and to the global population. (see: Collective Conscious Mind)
Spiritual Karma — based on a metaphysical level — is the result of an exchange of energy. This energy works in a vacuum of sorts where whatever type of energy is released now must be replaced with the same type of energy.
Let’s say that a person feels angry and starts taking their rage out on other people. As they do this they are at that very moment releasing energy out into the world. They are in fact releasing a low vibration of energy that impacts other energetic beings (people) in a negative way.
Since the exchange of energy in the universe works within a vacuum, this same type of energy must now be returned back to this person. Now of course this doesn’t mean that they will experience someone else yelling at them in rage, and it certainly doesn’t mean that this energy will come back immediately. What it does mean though is that they will receive in return something that is on the same vibrational level of energy as the rage they projected out into the world. For instance this could come in the form of an accident, or a misfortune of some kind that brings their vibrations to the same level that the other person experienced when they were yelled at with rage. (see: Vibrational Attraction)
Given all this, karma is more or less an exchange of energy on a spiritual level. Whatever energy you project out into the world, is the same level of energy you will eventually receive in return in the form of karma. As such, you effectively get what you deserve.