A social construction manifests into multiple forms of construction. Social means pertaining to society; a society is multiple people that voluntarily bind each other to a contract or are believed to born into a social construct;
this contract lays down multiple structures of living that unify the group.
The structures built are: racial, ethnicity, gender, sexual orientation, religious. These structures are legal structures that appear to essentialize the human in these social groups to a rigid role; if one defies these laws that one must to adhere to to be a legal racial identity, or ethnic identity, then ostracism occurs; punitivity is seen as the correcting devise to keep one following the law of one's imposed identity.
The construction aspect is a legal idea; it supposedly coheres individuals as one identity so nothing foreign can dismantle the group. It's as if individuals disappear, a mass just appears.
Interestingly, social construction may be seen a product of biological determinism; the social identity is a fixed and innate identity one is born with; it's as if biology, chemistry, physics constructs these social groups; religion believes these identities are God given, morality believes these identity allow for mutual and fluid activity amongst each other without friction.
This is the conservative position.
Social construction is seen as a fluid, individual, purely as an experiential identity. It's as if these identities are not actually objective identifies from the 'real'; these identities stem from the ideal; the ideal changes due to experiences not biological mechanisms such as cells, hearts and lungs. This gives forth a plurality of interpretations of what one identity means not just having different identities. The individual is free to derive their identity from personal experience relative to others within group, but also relative to other social groups; intersectional identities can be formed where different social groups interact to form new experiences that enhance unity not break apart unity.
Social construction is an extremely relative definition depending on whatever school of thought one adheres to. Objectivists will see sociy construction differently from the subjectivist, etc. Is social construction a social construction; depends on who you ask. It could be a synthesis of all perspectives.