A square space is defined to be as wide as the currently used font height.
This space is half as wide as a square.
This space is a quarter as wide as a square.
This space is a sixth of the width of a square.
Use this non-printing character e.g. to indicate word boundaries for computerized typesetting, or when using scripts that do not use explicit spacing. It is similar to the soft hyphen, with the difference that the latter is used to indicate syllable boundaries, and should display a visible hyphen when the line breaks at it. You can also use the zero-width space as a potential line-break in long words such as URLs which should not be hyphenated at all.
This space has a fixed width and is not taken into account for text breaks. Therefore it is recommended for use where you want to protect combined phrases against text breaks.
In monospaced fonts (like 'Courier New' or 'Monotype Sorts'), this space is as wide as one digit.
In monospaced fonts (like 'Courier New' or 'Monotype Sorts'), this space is as wide as the narrow punctuation.
Some languages (e.g. English or Czech) use words which are represented only by a single character. If these words should build an aesthetical group with the following word, rather than being left alone at the end of a text line, we recommend to use this so-called 'glue space'. You might also use one of the fixed width spaces (see above), but this will be seen in justified text.
The fixed spaces have a fixed width and will not be wrapped. The glue space has a variable width.
