English uses at least two types of dashes (en dash and em dash) along with hyphens, and there are (fairly complex, in my opinion) rules on when and how each should be used. What types of dashes or hyphens appear in Spanish? What are the rules governing their usage?
The Spanish names for the hyphen, en-dash and em-dash are guión, semiraya o raya menor, and raya, respectively. In Spanish, the en-dash is not widely used although, due to English influence, its use has become rather common nowadays.
The raya (em-dash) usually indicates separation; for example, it signals interventions of different characters in a dialogue and it also can be used to signal a new item in a list. The raya is also used to avoid repeating a word or a group of words.
On the other hand, the guión (hyphen) usually indicates union: of two words as in científico-técnico, of suffixes and words, as in intra-aórtico, and it is also used, as the hyphen, at the end of a line to indicate that a word will continue in the next line. The guión is also used between numbers forming an interval, as in pág. 178-185.
The following image shows a comparison of the three signs as produced by LaTeX using the palatino font at a font size of 80pt (the letters were included only to show the position of the symbols with respect to the text baseline):
Exceptionally well typeset materials will use anen-dash to signal a brief break in dialog which is introduced with an m-dash. I don't see it in a lot of publishers, but it works really well.
—Yo me llamo... –murmuró el niño– Emilio Sánchez Pérez.
In either case, whereas in English style will vary as to whether you put a space or not on both sides of the dash (but you do the same on both sides), in Spanish, you can tell whether a dash is opening/closing by where the space is.
texto y más texto —y más texto… <--opening
texto y más texto— y más texto… <--closing