The things that your program works with, such as integers (for example 5

One piece of data (for example the integer 5

A variable is a sort of box that can be used to store a value. The variable usually has a name and also a type. The type determines which values you can put in the variable.

A constant is in a way the opposite of a variable

A literal is a value of some kind, written in the program. "Hello"

A sequence of characters that can be used in a program as a name, of a variable or of something else. In Pike an identifier must start with an alphabetical letter or an underscore character ("_&q [..]

Values and variables have data types

Pike has type checking, which means that Pike keeps track of the data types of variables and values. If your program tries to put one type of value in a variable which was designed to hold another typ [..]

An expression is a piece of a program that gives a value when it is executed by the computer. An example of an expression in Pike is 5 * x + 7

A statement is a command that is part of a program, and that the computer can interpret and execute.