Cual es la diferencia entre "llevar" y "traer" ?
This is something easy to look up in the dictionary. They are kind of synonymous to each other though. Here are some things found in the dictionary on this site that should hopefully help you. If you just look them up you can see a whole lot more examples.
"LLevar" means "to carry/to take" EX: alguien se ha llevado mi sombrero -> someone has taken my hat
"Traer" means "to bring" EX: ¿has traído el dinero? have you brought the money?;
It's mainly a matter of directions, if you're speaking about something being 'taken' to a location different to where you are use 'llevar' but if you're speaking about something being 'brought' to where you are then use 'traer'.
Technically traer means “to bring, to carry with you”
Traje la coca => I brought the coke (with me)
Maria me trae las llaves => Maria’s bringing me the keys.
Whereas, llevar means "to take, to take out, to carry away”
Llevo la coca => I’m bringing the coke (i.e. I’m still at home, but will take it to another location wherever I'm heading)
Le llevo las llaves a María => I am taking the keys to María (i.e. they are here now, but I'm taking them to her)
Both verbs have other usages but these are the two most common ways to use them.
Possible ways: (I may forget a few)
Cual se lo lleva? Me lo llevo ese
Voy a llevar a mi hermano al concierto de Vicente Fernandez este sabado.