Social means to do with people and how they live together. Social life, social media, a social occasion.
It covers society at large — social policy, social change — and the smaller sense of being with people: a social evening, a social animal. In British informal speech, the social means social services or the benefits system: on the social, the social came round. As a noun, a social is also an informal gathering. Note sociable, which describes a person who likes company.
Too few real examples of this word to estimate which sense is commonest.
social is a quality relating to society.
Latin socialis comes from socius, a companion, from sequi, to follow. Associate, society and sequel come from the same following.
Middle French
social
English, today
social
Built from
Borrowed from Middle French social. From Middle French social, from Latin sociālis (“of or belonging to a companion or companionship or association, social”), from socius (“a companion, fellow, partner, associate, ally”), from sequor (“follow”). Cognate with English seg (“man, companion, fellow”). More at seg.
Etymology from Wiktionary, CC BY-SA