There are certain ways of life within the Church that are identified as “vocations.” This means that they are not merely life choices, or career choices. They are actually ways of life that God calls certain people to live. I think we are somewhat conscious of priesthood and religious life as vocations as calls from God. This is also true for permanent deacons. Some may not be aware that the Church also sees marriage as a vocation, a call from God, and not simply a personal choice that two people make.
    
Because these ways of life are vocations, they involve a period of discernment. Discernment is a time of questioning ourselves and checking our motives, asking ourselves why we think God is calling us to live this way. Simply wanting to be a priest, or a deacon, or a religious, or a married person, is not discernment. Discernment is not primarily a question of what I want to do, but of asking ourselves what God wants me to do.

The vocations to priesthood, diaconate and religious life have very organized processes that an individual must go through to discern if the call is actually from God or not. Marriage certainly involves asking oneself certain questions about whether I am called to marry, and if so, am I called to marry this person, but unfortunately, we do not have a structured process for doing so.