It's the first-person singular present tense form of the verb "querer" (to want).
Here are some examples:
* Quiero un café. (I want a coffee.)
* Quiero ir al cine. (I want to go to the cinema.)
* ¿Qué quieres comer? (What do you want to eat?)
* Quiero hablar contigo. (I want to talk to you.)