The use of hyphens to join words (such as well-read or jack-of-all-trades) and to separate syllables of a single word (such as when splitting the word on multiple lines) is called hyphenation.
Some software programs including word processing and page layout software have automatic hyphenation settings that break words at suitable points when they fall near the end of a line of text. Hyphens created automatically by the software are known as soft or discretionary hyphens.
Hyphenation is used to break up longer words at the end of a line in order to have a more even right side alignment. Adjusting the hyphenation zone -- the length or number of characters at the end of a line where hyphenation occurs -- affects the raggedness of the right side of the text in left-justified text. Hyphenation is also necessary when using fully justified text. Adjusting the size of the hyphenation zone may affect how much the words or characters are spread out or compressed in order to fill the line all the way to the right margin.
The software hyphenation settings are often referred to as Hyphenation & Justification or H&J.