It is a romantic phrase that suggests that someone has captured the heart of another person.
Here's a breakdown of the phrase:
* Tu: Your
* Corazón: Heart
* Es: Is
* Suyo: His/Hers
The phrase can be used to express:
* Love: "Your heart belongs to him/her"
* Devotion: "You are devoted to him/her"
* Commitment: "You are committed to him/her"
It is a very strong and meaningful phrase that can be used in a variety of contexts.