Depends on context.
Mujer by itself means Woman.
Mi Mujer (My woman) really means "My wife"
This is for the ladies.
Mujeres. (moo-heh-res)
"Acusan a las mujeres" means "they accuse the women" in English.
mujeres
You can say "zapatos para mujeres".
las mujeres
Mujeres desnudas.
Las mujeres son complicadas. You will notice that in Spanish, there are many instances of the definite articles for "the" (el, los, la, las) that we would consider to be extraneous in English. A Spanish speaker, for example, when asked to say "women are complicated" many times will revert to Spanish grammar, and say "the women they are complicated", which is the literal translation of "Las mujeres son complicadas".
"The women" in Spanish is "las mujeres".
¿Donde están mis mujeres?
"Tantas mujeres hermosas!"
tres mujeres jóvenes