A marriage license is a formal document that you need to have in order to get married. Different states in America have different sets of conditions regarding the license.
However, the basic criteria remain the same. The person authorized to perform the ceremony must have a copy of the marriage certificate by law.
The legal age for marrying in the UK is just 16. Scottish law does not need any parental consent unlike the laws in England and Wales. However, the laws in US are stricter. When citizens apply for a marriage license, then it is publicized in the paper. This way, they can verify if all the information provided are correct. The marriage license records are stored with the government for life. This helps in tracking down any particular individual if necessary. With the advent of the internet, you can even find out find your marriage license online. Thus, if you want your marriage to be legally registered, then you will need to have a valid marriage license.