Dash or hyphen?
There is a difference!  But many people do not know this.  You need to know when to use a dash or hyphen.
A hyphen (-) is used to divide words that split at the end of a line, or to join word parts into a single word, (as in prefixes.)  A hyphen is also often used to join two adjectives, usually before a noun.
A dash (— ) is a longer line: it is double the length of a hyphen.  A dash, also known as an em-dash, indicates a break or an interruption in the thought. Dashes are used to set off part of a sentence. Then there is the en-dash,  is slightly wider than the hyphen but narrower than the em-dash and  is used to imply range of numbers, dates, or time. and can be taken to mean “to” or “through.”

“The dash is a handy device, informal and essentially playful, telling you that you’re about to take off on a different tack but still in some way connected with the present course — only you have to remember that the dash is there, and either put a second dash at the end of the notion to let the reader know that he’s back on course, or else end the sentence, ahere, with a period.”

^__ Lewis Thomas

the dash or hyphen – examples of usage

A dash is used
–        to separate out a comment from the rest of the sentence.
“All three sisters—Jade, June and Jemima—are lawyers.”
–      to imply range of numbers, dates, or time. and can be taken to mean “to” or “through.”
“Read chapters 3-5 for your next test on this book.”

A hyphen is used
–        to join two or more words, mostly two adjectives before a noun.
weather-beaten face.
–        with prefixes, like self-, ex-, mid-,pro-,post-, etc
–        to divide a word, or at the end of a written line
self-harming
mid-month
word-processor
post-partum

NOTE:  There are no spaces between the letters when you use either a dash or hyphen. A hyphen (-) is used to divide words that split at the end of a line, or to join word parts into a single word, (as in prefixes.) A dash (— ) is a longer line and indicates a break or an interruption in the thought. Once you know the rule, whether to use a dash or hyphen is pretty simple to work out.