On 1 July 1837 civil registration was introduced in England and Wales, providing a central record of all births, deaths and marriages.
In some jurisdictions a marriage certificate is the official record that two people have undertaken a marriage ceremony.
In some other jurisdictions, a marriage license serves a dual purpose of granting permission for a marriage to take place and then recording the fact that it has done so.
Remember, in family research no matter where you get any information, you must always check it back to the original source.
You can not claim it as fact unless you have done this.