"Se llama" is used to say what someone's name is. It means "he/she/it is called."
Here's a breakdown:
"Te llamas" (you call yourself)
* Use: To ask someone their name.
* Example: "¿Te llamas Juan?" (Do you call yourself Juan?)
"Se llama" (he/she/it is called)
* Use: To say someone's name.
* Example: "Se llama María." (She is called Maria.)
Let me know if you have any other Spanish grammar questions!