Contractions are words that are contracted (shortened).
For example, forms of are (you're, we're, they're, etc) all show the shortening of [(a)re] by an apostrophe of omission ('). You are → you're, we are → we're, etc.
Don't use contractions, like
don't, I'm, isn't, etc, in formal writing. They especially should not be used in academic English.
Just to be clear, 'women's shoes' shows a (correct) use of the possessive apostrophe. It is not a contraction. Therefore you may - indeed should - use it.
- In various forms of biology, health studies, anatomy and so on, the word contraction refers to the shortening of muscle tissue. A mother will experience contractions in her womb which begin the process of giving birth. In other technical fields, there are other technical meanings. Note the difference between the verb contract in this sense of 'to shorten' and the noun 'a contract', which is a legally binding agreement between two parties.
- You may also want to see a page distinguishing different meanings (and pronunciations) at contract.