is a structured data type in Object Pascal. Which are able to contain variables, functions, procedures like a record, however a class uses access scopes, allowing one object to inherit variables and methods from another - saving on design time.

type
   vehicle = class
      doors:byte;
      seats:byte;
      function availableColors:TStringArray;
   end;

Now depending upon the type of manufacturer, these could be street vehicles and have the following descendant classes that inherit those 3 elements:

type
   car = class(vehicle) // <-- so a car inherits everything from vehicle.
      engineType:avalableCarEngines;
      sportsPackage:Boolean;
   end;

   truck = class(vehicle)
      engineType:availableTruckEngines;
      offRoadPackage;
   end;

There is more code needed to instantiate the classes into objects in memory, we are keeping this brief to show the conceptual benefit of a class.

var
   MyAuto:car;

Begin
   MyAuto.Init;
   MyAuto.Doors:=2;
   MyAuto.Seats:=4;
   MyAuto.engineType:=CarV8;
   MyAuto.SportsPackage:=True;
{... more code here ...}
   MyAuto.Free;
End.

Source: Reserved Words

See Also:

record.