When a couple files for divorce, there will be a lot of work that needs to be done. Both spouses need to agree on a bevy of issues, and any that they can't agree on will go to a judge. Once finalized, the divorce agreement will rule over their post-divorce lives. Both spouses at that point may breathe a sigh of relief and think "well at least I don't have to think about or deal with that again."
However, this isn't the right way to think about your finalized divorce agreement, nor your divorce in general. There will be life events that transpire in the months and years that follow that will require both you and your spouse to either come to the negotiating table or to court.
Consider, for example, if the two of you have a child. Custody will obviously be a big issue, but in the months and years after your divorce, you may need to move to a different city or state -- or your former spouse may need to do the same. A modification to your custody arrangement will be in order.
Similarly, what if your financial situation drastically changes, or your former spouse's? This could impact everything from child support payments to alimony payments, and many other issues integral to the divorce arrangement. Again, a modification is likely in order.
Modifications and post-divorce litigation can be confusing and intimidating. But you don't have to deal with it alone. Consult with an experienced family law attorney to ensure your case is handled properly.