A noun which denotes a collection of individual persons or objects is called a collective noun.
Examples are: crowd, mob, team, flock, herd, army, fleet, jury, nation, family, committee, government etc.
In British English, a collective noun may be treated either as singular (if the whole group is being thought of as a unit) or as plural (if the group is being regarded as a collection of individuals).
The committee has announced its decision. (The committee is regarded as a unit.)
The committee are divided on this issue. (The committee is regarded as a group of individuals.)
In American English, a collective noun is always treated as singular, and Americans say The committee is divided on this issue