Should I teach my child competition or collaboration -which is more important?

I would say both. Collaboration will teach your child to work as a team, while competition will teach about survival and how to achieve the best. For collaboration, teach your child how to interact with others and work together in a team, instead of trying to do everything in one's own way. For competition, teach your child how to set goals and work hard to achieve them. For both the situations, the idea should be to do the best possible, instead of trying to hurt someone else and do good.