Whitespace refers to characters that are not visibly rendered on screen. This includes space (U+0020), tab (U+0009), newline (U+000A), and full-width space (U+3000), among others.

The CSS white-space property controls how whitespace is displayed. With normal, consecutive whitespace collapses into a single space; with pre, it is preserved as-is. CSS layout practical guides teach whitespace control techniques.

In programming, whitespace handling is critical. Python uses whitespace for indentation, JSON file sizes are affected by extra whitespace, and the regex s matches whitespace characters.

Unicode defines many types of whitespace: non-breaking space (U+00A0), zero-width space (U+200B), and ideographic space (U+3000), each serving different purposes. Text processing programming books explain accurate whitespace handling.