Children is the plural form of child, referring to young human beings below the age of puberty.
In a broader sense, children can also mean:
1. Offspring of any age (e.g. "They have three grown-up children")
2. Figuratively used to describe inexperienced people ("Don't be such a child!")
3. In computing, referring to subordinate elements ("child processes")
4. In genealogy, direct descendants ("children of Abraham")