A good answer might be:

A buffer is a section of memory used as a work area.

Disk input and output is more efficient when a buffer is used. For our small example programs it doesn't matter much. However, programs that do extensive IO should use buffers. The BufferedWriter stream is used for this with a character output stream.

BufferedWriter(Writer out)  
    Construct a buffered character-output stream 

Usually the constructor is used as follows. Since FileWrite is a Writer it is the correct type for the parameter.

BufferedWriter out
   =  new BufferedWriter(new FileWriter("stuff.txt"));  

BufferedWriter has the same methods as FileWriter plus an additional method:

newLine()
    Write the line separator that is used on make of
    computer on which the program is running.

Different makes of computer (IBM, Apple, VAX, Sun) separate lines of text in different ways. The newLine() method outputs the correct characters for the computer it is running on.

QUESTION 13:

Is the '\n' character always appropriate at the end of a line?