[Koha] koha 3 zebra

hi i installed koha 3 on ubuntu i have a problem in saving records i searched for tha error in internet and try every thing with zebra and yaz finally when i run rebuild no zebra it's working good and save record i want to know the difference between when i run zebra and no zebra in spite of i was choose zebra in first installation page and ant another solutions for saving records ..... thank's