What is Sephardi?
1.
The term Sephardi, as generally used, describes Jews of non-European origin. The term is actually a misnomer in that it broadly describes Jews of middle-eastern descent as well Yemenite Jews. The term "Sehpardi" actually means "Spain". Jews of Middle-eastern descent should really be called "Musta'Arab" or "Edot Hamizrah". Jews from Yemen are not Sephardi at all either and should be referred to as "Temani" (or another more appropriate term they themselves use - which I have forgotten at the moment).
Spanish (and Portugese) had existing communities in Turkey and Greece and even in Holland which developed after the expulsion from Spain, circa 1492.
Sephardi Jews, as used broadly, have unfortunately come to assimilate among the more dominant and hegemonic Ashkenazi Jews. Consequently, they have almost lost their rich culture, heritage, norms, and traditions
Sephardi Jews have different traditions or minhagim than Ashkenazi Jews.
In many cases, Sephardi Jews abide by significantly different Halachot than Ashkenazi Jews.
Beyond just food and liturgical differences, Sephardic Jews have traditionally had a different approach to Judaism. They are not as neurotic in their adherence to the laws as Ashkenazi Jews.