In Spanish noun is "Sustantivos", all nouns are either masculine or feminine. The definite article (English "the") agrees with the noun and gender (masculine or feminine) and number (singular or plural)
The masculine singular noun takes the definite article “el”
Most nouns that end in -o are masculine.
Here are some examples of common masculine nouns in Spanish
amigo friend
banco bank
baño bathroom
carro car
gato cat
libro book
muchacho boy
niño little boy
perro dog
teléfono telephone
vino wine
The Feminine singular noun takes the definite article “la”
Most nouns that end in -a are feminine.
Here are some examples of common feminine nouns in Spanish:
amiga friend
blusa blouse
bolsa bag
casa house
cama bed
cerveza beer
comida meal
hermana sister
iglesia church
lámpara lamp
mesa table