Hi!
SOP or statement of purpose , describes your academic background and strengths. A good SOP should be fit with the university as well as the program you are applying for.

Ideally you should write a separate SOP for each program you apply for so that it is fit with the university and indicate that you know about and are interested in that specific program. But you might not have time to write so many SOPs and the major part is same in SOP, so you can take time and write one good SOP and then change the particular part of SOP according to the program you apply for different universities.

To know the format and guidelines for a perfect SOP , follow the given link:
https://www.google.com/amp/s/studyabroad.careers360.com/articles/how-write-best-sop/amp