Where is the soul and what happens to it after it is taken, and what is its fate if its owner was righteous or an infidel?

The fate of a human soul after death varies depending on the state of the deceased.

The soul of a believer: Angels of mercy ascend with it to the seventh heaven, then it returns to the body in the grave. There, it is questioned about its Lord, its religion, and its Prophet, and it answers correctly. Its grave is then laid out with provisions from Paradise, a door to Paradise is opened for it, its grave expands, and its righteous deeds come to it in the form of a handsome man.

The soul of a disbeliever: Angels of torment take it to Sijjin in the lowest earth, then it returns to the body in the grave. There, it is questioned but cannot answer. Its grave is then laid out with provisions from the Fire, a door to the Fire is opened for it, and its grave constricts around it.