In the photographs, the quasars look like star-shaped objects, so they cannot be recognized by their appearance. The differences between them are manifested in the spectra. In contrast to stars, the spectra of quasars contain bright and broad emission lines. In this case, the spectral lines are strongly redshifted due to the Doppler effect (as in distant galaxies). In addition, quasars are sources of radio emission.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.