Difference between courtship and marriage

Courtship is a period during which a couple develop a romantic relationship, especially with a view to marriage.

Marriage is the legally or formally recognized union of two people as partners in a personal relationship.

The difference would be the stage of the relationship based on the definition. courtship is like "dating."

Courtship is a period during which a couple develop a romantic relationship before getting married. This occurs before marriage.

While

Marriage is the joining together of a man and woman to become husband and wife