How did the sephradic jews who immigrated to israel differ from the ashkenazi jews?

They differ in some social and ritual customs, and in some aspects of their cuisine.

These 'surface' differences stem from their respective historical geographic origins.  The history of the 'Sephardim' springs from western Europe and North Africa, including Spain, Portugal, Turkey, Morocco, Egypt, and Arabia.  The history of the 'Ashkenazim' is rooted in Eastern Europe, including Germany, Poland, the Baltics, Russia, and the 'Stans' ... Tajik, Kazakh, Uzbek, etc.

One fascinating feature of this split, isolated evolution of Judaism ... and there are many ... is the fact that even though the two streams evolved, with almost zero contact, for as much as 1,000 years, a Sephardic Torah scroll and an Ashkenazic Torah scroll are totally identical, down to the last character in every one of their 10,290 lines of text written in 245 columns.