A
computer jargon term used to describe all the
characters that don't
display any
visible symbol. Besides the
space character, whitespace also includes the
tab character, the
return character, the
line break character, and in some environments, the
non-breaking space character and other weird spaces.
In HTML, all sequences of whitespace characters in the codes are represented as a single space for presentation purposes, except in a <PRE> block.