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"Lavaplatos" is a noun which is often translated as "dishwasher", and "lavadora" is a noun which is often translated as "washing machine". Learn more about the difference between "lavaplatos" and "lavadora" below.
el lavaplatos(
lah
-
bah
-
plah
-
tohs
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
a. dishwasher 
Mañana viene el técnico a arreglar el lavaplatos.The repairman is coming tomorrow to repair the dishwasher.
Cuando acabe el lavaplatos, vacíalo.When the dishwasher is done, unload it.
This means that the noun can be masculine or feminine, depending on the gender of the noun it refers to (e.g., el doctor, la doctora).
3. (profession)
a. dishwasher 
Durante las vacaciones de verano, trabajaba como lavaplatos en un restaurante.During summer vacation, I worked as a dishwasher in a restaurant.
la lavadora(
lah
-
bah
-
doh
-
rah
)A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
a. washing machine 
La secadora todavía funciona, pero necesitamos comprar una lavadora nueva.The dryer still works, but we have to buy a new washing machine.