CHAPTER 0  Introduction  O.A. An Overview of Pascal Programs  Much of the following text assumes that you, the reader, have a minimal  grasp of computer terminology and a "feeling" for the structure of a  program. The purpose of this section is to spark your intuition.  An  algorithm  or computer program consists of two essential parts, a  description of  actions  that are to be performed, and a description of the  data, that are manipulated by these actions. Actions are described by  so-called  statements,  and data are described by s<r-Called  declarations  and  definitions.  The program is divided into a  heading  and a body, called a  block.  The heading gives the program a name and lists its parameters. These  are (file) variables and represent the arguments and results of the  computation. The block consists of six sections, where any except the  last may be empty. They must appear in the order given in the definition  for a block:  Block  =  LabeLDeclarationPart  C  onstantDefinitionP art  TypeDejinitionPart  VariableDeclarationP art  ProcedureAndFunctionDeclarationPart  StatementPart .  1 