Income derived from Social Security is currently estimated to keep roughly 20% of all Americans, age 65 or older, above the Federally defined poverty level. The Social Security Administration is headquartered in Woodlawn, Maryland, just west of Baltimore.
Control is the term used to describe an object in a window or dialog box. Controls include push buttons, scroll bars, radio buttons and pull-down menus.
The usual objective of control theory is to control a system, often called the plant, so its output follows a desired control signal, called the reference, which may be a fixed or changing value. To do this, a controller is designed, which monitors the output and compares it with the reference.