Parivartana yoga indicates the initial condition and the later condition, but also; the planets involved in the parivartan yoga indicate what kind of situation will lead to the parivartana.
For example, if the 10th Lord (Sun) is afflicted with Saturn and debilitated in the 12th house but Venus (which is also the the 7th Lord) is there in 10th house, there is an exchange between Sun and Venus. The yoga will get activated by marriage and it can be said that career and financial status will grow after marriage.
Parivartan is a Hindi word which means “Exchange“. Mutual Reception or Parivartan means exchange which can be of Signs/Nakshatra or Aspects between two planets. Parivartan not only means exchange of signs- it denotes exchange of power, energy, natural nature of each other and everything. Whenever there is an exchange of signs between planets it means they are in mutual connection with each other and will work together.