Isn’t ‘annulment’ a fancy word for divorce? What’s the difference?

Nope, they are really different things.

A divorce is basically the breaking apart of a validly contracted marriage. In the eyes of the state, a marriage isn’t indissoluble. It can be real and still be dissolved later. In the eyes of the Church, it is much different. Marriage is sacramental, indissoluble, and not just a simple contractual obligation one can extricate themselves from whenever they choose.

God is involved and he ties the knot by his own power so no man has the power to undo it. The Church recognizes that before God a valid marriage between two baptized people can never be dissolved, and as long as they’re alive, the couples are bound to each other.

So the Church recognizes that even She has no power to dissolve a validly contracted sacramental marriage.

An annulment, on the other hand, is not a decree or some judicial ruling seeking to separate validly married couples. It is a decree that, after a careful investigation, there was never a valid marriage in the first place. That the couple never met with sacramental prerequsites and were never validly married in the eyes of God and the Church.

There are some conditions that must be present for a real Christian union to occur. For instance if one is forcefully given by her parents to a man, or a partner never intended to be faithful or open to consumation and children, the marriage cannot be validly contracted befoore God. There are many other conditions though but these are just examples.

Jesus mentioned this “unless the [first] marriage is unlawful”—that is, null (Matt. 19:9, NAB).

Therefore, an annulment does not end a real marriage but declares that it was never a valid, sacramental marriage from the start. The Church can never support divorce since it goes against the very nature of the Sacrametal Union.