Final answer:
Interpersonal relationships include a variety of associations between two or more people that can be formal or casual, while close relationships are characterized by emotional depth, trust, and significant personal disclosure. These differences are exemplified in the theory of love, which categorizes relationships by varying levels of intimacy, passion, and commitment.
Step-by-step explanation:
An interpersonal relationship is a connection between two or more people that can range from fleeting to lasting, which may be founded upon social commitments, professional interactions, or other forms of social linking. These relationships are often situational, and while they can be meaningful, they don't necessarily involve a deep level of emotional connection or personal disclosure that close relationships do.
Conversely, a close (intimate) relationship typically denotes a deeper, more meaningful connection often characterized by emotional bonds, trust, and ongoing personal disclosure. Such relationships are considered primary groups, where close ties and complex interpersonal dynamics are present, often including family members or close friends.
Stages of love as outlined by Sternberg illustrate the varying depths of relationships, reflecting different levels of intimacy, passion, and commitment, which distinguishes between types of bonds ranging from simple friendships to romantic and family ties.