— As an emerging research method to deal with information and knowledge processing, various topics of granular computing have recently received more attention by researchers. The foundations of granular computing involves general principles of many disciplines that are explored for many years such as divide and conquer, interval computing, fuzzy sets, rough sets and so on. Granules, granulations and relationships are some of the key issues in the study of granular computing. This paper aims to understand mainly granular computing theory from the perspective of information granulation and granular relationships.