An Indirect Object, or complemento/objeto indirecto, tells to whom or for whom the action is done. It is the part of the sentence that indirectly receives the action of the verb. It usually refers to a person.

Mamá siempre me compra ropa.	Mom always buys clothes (for whom?) for me.
Nuestra abuela nos escribe todos los meses.	Our grandma writes (to whom?) to us every month.

Ejemplos:

me	Mi amigo me dio una blusa.	My friend gave me a blouse.
te	Tus padres te dieron una bolsa.	You parents gave you a bag.
le	Le compré unas medias a José.	I bought him a pair of socks.
nos	Mamá nos envió una postal.	Mom sent us a postcard.
les	Les di los boletos para el cine.	I gave them the tickets to the movies.

As is the the case with the direct object pronouns, indirect object pronouns may replace the indirect object nouns.

¿Qué le regalaste a Pepe?	What did you give to Pepe?
Le regalé un cinturón.	I gave (to) him a belt.

Since le and les have a number of different meanings, the indirect object pronouns are sometimes used together with the corresponding indirect object noun (preceded by "a") or prepositional phrases (a él, a ella, a usted, a ellos, a ellas, a ustedes) for clarification when the context is unclear.

Ejemplos:

Le compré una guayabera a papá.	I bought a guayabera for Dad.
Les mandamos los regalos a mis primos.	We sent the presents to our cousins.
Le compré unas medias a José.	I bought him (José) a pair of socks.
Le conté la historia a él.	I told him the story.
No les compré nada a ellos.	I didn't buy anything for them