janm kundali ke barah bhavon se bhinna-bhinn baton ko dekha jata hai. jyotish ka mul niyam yah hai ki bhav ki shubhashubhta ka vichar bhav aur bhavesh ki balavatta aur us par parne vali anya grahon ki yuti evan drishti dvara nirnit hota hai sath hi nitya karak grahon se bhi bhav ki shubhashubhta ka vichar karte hain. is prakar bhav, bhavesh aur karak in tinon ke sanyukt prabhav ke falasvarup bhav fal ka nishchay kiya jata hai.
yahan ham karak aur unke mahatva ki charcha karenge. karak do prakar ke hote hain- sthir karak aur char karak. sthir karak ka arth yah hai ki kisi bhi lagn ki kundali ho aur koi bhi rashi jatak ki ho sthir karak men koi antar nahin ata hai arthat sthir karak grah anshadi sapeksh nahin hai. pitri karak grah vah hai jo surya aur shukra men bali ho arthat surya aur shukra ki sthiti jatak ki kundali men kya hai is par vicharoprant donon men jo bali siddh hoga vahi grah pitrikarak mane jayenge. matrikarak grah vah hai jo chandrama aur shukra men balvan siddh hota hai.
isi prakar mangal grah se bahan, sala, chote bhai ka vichar kiya jata hai. budh grah se chachi, guru se pitamah ka, shukra se svami ka aur shani se putra, pita, sas-sasur, matamah, matamhi adi tatsaman janon ka vichar karna chahie. iske atirikt barah bhavon ke bhi karak kahe gaye hain- lagn athva pratham bhav ka karak surya hai. dvitiya bhav ka guru, tritiya bhav ka mangal, chaturth bhav ka chandrama, pancham bhav ka guru, chathe bhav ka mangal, saptam bhav ka shukra, ashtam bhav ka shani, navam bhav ka guru, dasham bhav ka budh, ekadash bhav ka guru aur dvadash bhav ka karak shani hai in sthir karkon ke bad char karak ka prasang ata hai.
char karak grah vah hain jo jatkon ke kundaliyon men unke grahanshon ke adhar par nirnit hote hain. chunki alg-alag kundaliyon men grah ke anshadi alg-alag hote hain islie ye karak bhi sthir n hokar badlte rahte hain. janm patrikaon mane jis grah ka ansh sabse adhik hota hai vah atmakarak kahlate hain. usse kam anshadi vala grah amatya karak arthat mantri, usse kam anshadi vala grah bhatri karak, usse kam ansh vala grah matrikarak, usse kam ansh vala grah pitrikarak, usse nyun ansh vala grah putra karak, usse kam ansh vala grah gyati karak aur usse bhi kam ansh vala grah dara karak hota hai. kuch vidvan matri karak aur putra karak grah ek hi mante hain. char karak nishchay karne men ansh se lekar vikla tak vichar karna chahie. yadi grah ek hi karak ke pratinidhi mane jate hain.
is sthiti men usse age vale karak ka lop ho jata hai. tab us karakatva ka nirnay sthir karak se karne ka vidhan shastron ne diya hai. uprokt char karak ath ho gae hain parantu grahon ki sankhya ravi se shani paryant sat hi hai. atah vidvan rahu ko bhi char karak nirnay men sthan dete hain. parantu rahu ke karak vichar men rahu ke ansh ko 30 digri men se ghatakar samjhna chahie kyonki rahu sadaiv ulta chalta hai.