"Karma" comes from Sanskrit "To do". If you perform any action willfully and awareness is involved, then it is karma. So mobile and any instruments don't have any awareness, so it cannot be considered as karma. Yog meaning unite to greater goal. Karma yoga is a method to convert everyday action to elevate our consciousness.
What bhagavath geetha says about Karma.
Meaning of the above sloka:
"The body, the doer, the various senses, the many kinds of efforts, and Divine Providence—these are the five factors of action. "God is seated within the body of the living being as the witness. Based on their past karmas, he also grants different abilities to different people to perform actions. We can call this Divine Providence."
For example, some people possess the acumen for earning huge amounts of wealth. Their acquaintances become astonished by them Brilliant financial analysis of complex situations. They also seem to be lucky with The risks they take. This special intellect is granted to them by God.
Similarly, Others seem to have God-given talents in fields such as sports, music, art, literature, etc. It is God who bestows people these special abilities, in accordance with their past karmas. He also grants the results of the present karmas. Hence, he is listed as one of the factors responsible For action."
Karma can be mainly classified into 3 Types:
All karma will bear fruit sooner or later, whether we like it or not. We encounter various situations in our life because of Sanchit karma. The karma we perform in our everyday life is all Kriyaman Karma.
For example, We want to eat food, and we eat. The karma is over there and it's not carry forwarded. But there are some karma where the immediate result is not happened. Such karma are so collected as "Sanchit". They end when they bear fruit at different stages of our lives.
Sometimes it takes many births to bear fruit, but it is not over until it bears fruit. Then it becomes our 'prarabdha'(destiny). This is the reason for some people having good family surrounding and some with no wealth or friends etc.
We cannot freely choose our destiny, as it is the result of our past karma. But kriyaman karma we are free to do. It is our present karma that determines our destiny as said by Krishna.
People often ask a question why the good person struggles and the bad gets better and better. The wicked person is praised, He is wealthy and everything surrounding him looks good even after so much of the evil in him. The reason is just because of his past karma.
In Mahabharata, Bishma had to go through so much pain in the war and Bishma asks Lord Krishna why he had to suffer so much pain even though he did no bad karma in his whole life. Krishna replies it's because of his past karma. Lord Krishna explained to him that it was his karma 71 births ago when, as a hunter, he pricked a butterfly with a stick and made holes in its body.
Your karma is you. Karma defines you. How you perform any action decides your complete life. Fate happens when you don't take any conscious decisions. You are driven where the life takes you. Karma Yog enable you to develop leadership qualities within you. A leader should be able to see all sides.
Detach from will for personal gain, then what ever action you do will become Yog. Action for a larger purpose for others become karma into yog.
Example: You sweep a floor and the floor is swept. So you helped your mom, that purpose is satisfied. With what motive, it is done that has become a sanskara in your mind. If you help your friend because he is a friend, then that caring and friendship became a sanskara in your head. This will make you generous. If you helped because your teacher told to help, so obedience became sanskara.
If you helped because you are thinking that one day he will also help you, then barter became your sanskara. So in bhagavath geetha it says that intention and motive is very important. Any work has 2 effects, internal and external. Internal effect is sanskara, external is visible
Third effect is karmaashai. That is, if you help someone, then at some point of time you will also receive help. This is like newtons 3rd law. Every action has an equal and opposite reaction. What you sow, is what you are going to reap. You throw positive force, it will come back in time.
What ever you do is karma-yog people say. It's a necessity for people to work. Karma yoga is changing a subject (you) with an objective means. It's mandatory for you to contribute to the society. The food you get are the efforts of so many people working behind.
It's nothing great to do karma yoga because you have taken so much from your society. Life is to give. When you give, you get happiness. Try to give as much as possible. There is no use of learning, karma yog without having a natural tendency to contribute to people. You want to be always happy, then try to always give, not take.
The universal law of karma is causation. Every effect has a cause. This theory is based on karma yog. With every situation you are facing now is your past karma. So cause and effect have always been in a relationship. What every cause I am having now can we fix it ? Can we change karma at any point?
We have freedom to change it. You are in charge of your future. Nothing is prefixed. Through your decision and will, you can change everything. Vivekananda used to say, you are the creator of your destiny. A thought is a mental karma. Any negative things what is coming into your life, don't let your intelligence take control of it.