Most of the descriptions are taken from the Wikipedia free encyclopedia.

Object Pascal is an extension to the Pascal language that was developed at Apple in consultation with Niklaus Wirth, the inventor of Pascal. It is descended from an earlier attempt at an object-oriented version of Pascal called Clascal, which was available on the Lisa computer.

There are actually very few syntactic additions to Pascal in Object Pascal. A new data type is added, the object. An object is very much like a record in that it can have multiple data fields of arbitrary types. In addition, you can specify a list of procedures and functions, referred to as methods, for a particular object type.