There are multiple stages of a marital break-up, with the two biggest being divorce and separation. While these are similar, there are some key differences that must be noted in Ontario.
A separation is just a physical split. This is when you and your spouse decide not to live together any longer. This term is used for traditional marriages and for couples who live together without getting married. The separation could be as simple as your spouse moving out of the house and into an apartment.
It is important to note that couples can be separated and still married.
A divorce, on the other hand, is the legal term for the dissolution of the marriage. It never applies to unmarried couples who live together, as they can't be legally divorced if they were not legally married. A divorce has to be finalized by the court, and the marriage is then officially done.
There are many reasons this is an important distinction, such as when determining the division of assets. Your assets will often be valued at the point you separated, and the division will be based on what was owned at that point as well. The reasoning behind this is that some couples separate for a long time—months or even years—before getting an official divorce, and so only property that they owned while they were together may end up being divided between the two of them.
If you and your spouse are having troubles, be sure you know all of your legal rights and how they pertain to the official status of your relationship, as it moves through the various stages of the split.
Source: Government of Canada Department of Justice, "About Divorce and Separation," accessed Oct. 29, 2015