Differences are an absolute given in every relationship. We are rarely attracted to people who are carbon copies of ourselves. Every couple has different personalities, opinions, experiences, family backgrounds, and reactions to certain things. The trick is to not allow the differences to turn into conflicts.
Conflicts occur in a relationship when one person tries to make the other say, do, think, or feel a particular way. Naturally, the other person becomes resistant or defensive because they don't want to feel dominated or controlled.
How do you prevent differences from becoming conflicts? Defend your partner's point of view.
The next time you're having a fight, take on the role of your boyfriend, girlfriend or spouse's defense attorney. Try to prove why they have a right to be upset. Specify it in concrete terms. By trying to understand instead of change your partner, you won't be met with defensiveness or anger.