hey uamir...
Let me tell you there is no similarity between them.
SPP= Student Partners Program. It is partnership between Canadian visa offices in India and community college association(ACCC). There are 42 institute listed under SPP category as now. Better you Google it and you will get to know.
else go to this website:- http://www.canadainternational.gc.ca/india-inde/visas/StudentPartnersProgram_ProgrammePartenairesEtudiants-Nov09.aspx?view=d
SOP = Statement of Purpose. It is a one of the brief and personal statement about who you are, what has influenced your career path, and all about your career goals and professional interest and why you are interested in particular subject or course. what is the main reason behind it and where you want to go from here. that's all.