It refers to the blessings before and after saying "Shema Yisrael" morning
and evening. In the morning there are two blessings before 'shema' and one
after. In the evening there are two before and two after. Total = 7
(source: Talmud tractate Berachot)
> Muslims have five services daily. Does this have some basis in Judiasm?
As it happens, we do have a day with five services: Yom Kippur!
Ohr Somayach Jerusalem