Karma is a word from the Sanskrit root 'kr,' means to perform a deed or action, it also includes actions that we do, not only through our body, but also through speech and mind, like you reading my text is also karma and after thoughts are also karma, me writing and answering you is also karma and what I am thinking while writing and after writing is also karma,
Lets say we went for hiking and reach a mountain top, and from their you shouted"you are ugly" what will you listen, the same words echoed in exact, and I know you wont like the igy to return, so you shout "I am beautiful" and which you would like to hear, give what you would want to receive.
The above is core of Karma or basic principle , karma means action and reaction, that is the echo, all reactions are like ‘echos’ of your previous actions; the fruits will be inevitable, and what does the mountain illustrate here? it tells you that the world is your own projection, what you were referring to as karma, is really a projection,
So karmas travel birth after birth until one finally start echoing unconditionally the echo which resonate without forced conscious, its just there, happening without your will or thoughts,
If I did wrong today and next day something good, that doesn’t mean the effect of wrong will disappear, but it will diminish but never be erased, we have to face the music, of both, good or bad, sooner or later, this or that life,
It’s all about balance of your thoughts and action one performs, I can go on and on, I would love to answer questions because this is never ending sharing but crux is, whatever we are today is of our past karmas (our thoughts and actions), which can only we freed once we realize that we are not just body or spiritual veda or xyz but a soul,