The usage of the verbs venir (to come) and traer (to bring) are a little different in Spanish (I am told that it is the same as in British English). The main difference comes with the destination of venir and traer.
In Spanish, venir means to come, but only if the destination is HERE, not elsewhere. Anywhere else, you go with ir.
The same goes with traer which means the same as llevar (to take something or someone from one place to another). The difference is that the destination of traer is ONLY HERE. If the destination is elsewhere, you have to use llevar.
For example in English, if you were speaking with a coworker at the office you may say:
“There is going to be a party in my house in the suburbs. You may come and bring your wife too.”
So obviously the party is not here, so (in Spanish) you cannot come or bring, but have to go (ir) and take (llevar). In Spanish we would say:
“Va a haber una fiesta en mi casa en los suburbios. Puedes ir y llevar a tu esposa también.”