What are the names of the U.S.cabinet level departments?

The 15 departments of the US executive branch (the cabinet) are :

Department of Agriculture

Department of Commerce

Department of Defense

Department of Education

Department of Energy

Department of Health and Human Services

Department of Homeland Security

Department of Housing and Urban Development

Department of the Interior

Department of Justice

Department of Labor

Department of State

Department of Transportation

Department of the Treasury

Department of Veterans Affairs

The executive who runs a department is called a Secretary (e.g. Hillary Clinton is the Secretary of State). The exception is the Department of Justice, which is headed by the Attorney General.
They run the 14 Executive Departments (departments of State, Defense, Treasury, etc.) and provide advice to the president.