The difference between "llevar" and "traer" in Spanish is primarily related to the direction of the action:
Llevar (To take)
Explanation: "Llevar" is used when the action is moving something or someone from the speaker's current location to another location. It implies taking something away from where you are.
Example: Voy a llevar el libro a la biblioteca. (I'm going to take the book to the library.)
Traer (To bring)
Explanation: "Traer" is used when the action is moving something or someone towards the speaker's current location. It implies bringing something closer to where you are.
Example: Puedes traer la pizza a mi casa? (Can you bring the pizza to my house?)
Summary:
Use "llevar" when the movement is away from the speaker's current location.
Use "traer" when the movement is towards the speaker's current location.