Input stream
Sequence of characters coming into your program from an input device.

Extraction operator
Operator used with cin to extract a value from the input stream.

File position pointer (aka "reading marker")
Keeps track of the point in the input stream where the computer should read next.

End-of-file marker
Invisible character at the end of every file which indicates where the file ends.

Text file
File containing only ASCII characters.

get function
Inputs the next character waiting in the input stream, as in -- cin.get(ch);

Interactive program
System that allows direct communication between the system and the user.

File
A named area in secondary memory that holds information.

Opening a file
Preparing it for reading or writing.

Levels of abstraction
In top-down design with stepwise refinement, the level of detail with which the algorithm is represented, with the root node itself representing the highest level of abstraction and the algorithm represented by the leaves as the lowest level of abstraction.