This visa category is issued to the immediate family members (Spouse and Children only) of the principal applicant. Parents are not entitled for a depended visa even though they are dependent to the principal applicant. The dependents are allowed to work. In many countries, Childs dependent visa is not issued to children above 18 years of age.
In few countries the dependents are allowed to work with few restrictions as long as the principal applicant is holding a valid work visa and working in the country the dependents are allowed to work. Countries like Australia, Canada, Netherlands, UK and US allow dependents to work on their dependent visa.