Nouns in French have this particularity to be either masculine or feminine. Not that they belong to the masculine or feminine sex because why a word such as "table" belongs to the feminine? These are word genders.
Masculine
words have the article: un or le
Feminine words have the article: une or la
Feminine words have the article: une or la
The
plural for un/une is des.
The
plural for le/la is les.
You
must learn the word with the article because there is no rule to remember which
one is masculine or feminine, except for animals or human beings.
Example:
un
stylo = a pen
une
maison = a house
le
cahier = the notebook
la
pluie = the
rain
des
voitures = cars
les
enfants = the children