Table 2.

Terms commonly found in the scientific literature that are distinct but related (adapted from the US Surgeon General's Advisory ⁴ )

Term	Definition
Loneliness	A subjective distressing experience that results from perceived isolation or inadequate meaningful connections, where inadequate refers to the discrepancy or unmet need between an individual's preferred and actual experience.
Social capital	The resources to which individuals and groups have access through their social connections. The term is often used as an umbrella for both social support and social cohesion.
Social cohesion	The sense of solidarity within groups, marked by strong social connections and high levels of social participation, that generates trust, norms of reciprocity, and a sense of belonging.
Social connectedness	The degree to which any individual or population might fall along the continuum of achieving social connection needs.
Social connection	A continuum of the size and diversity of one's social network and roles, the functions that these relationships serve, and their positive or negative qualities.
Social disconnection	Objective or subjective deficits in social connection, including deficits in relationships and roles, their functions and/or quality.
Social infrastructure	The programs (such as volunteer organizations, sports groups, religious groups, and member associations), policies (such as public transportation, housing and education), and physical elements of a community (such as libraries, parks, green spaces, and playgrounds) that support the development of social connection.
Social isolation	Objectively having few social relationships, social roles, group memberships, and infrequent social interaction.
Social negativity	The presence of harmful interactions or relationships, rather than the absence of desired social interactions or relationships.
Social networks	The individuals and groups a person is connected to and the interconnections among relationships. These “webs of social connections” provide the structure for various social connection functions to potentially operate.
Social norms	The unwritten rules that we follow which serve as a social contract to provide order and predictability in society. The social groups we belong to provide information and expectations, and constraints on what is acceptable and appropriate behavior. Social norms reinforce or discourage health‐related and risky behaviors (lifestyle factors, vaccination, substance use).
Social participation	A person's involvement in activities in the community or society that provides interaction with others.
Social support	The perceived or actual availability of informational, tangible and emotional resources from others, commonly one's social network.
Solitude	A state of aloneness by choice that does not involve feeling lonely.