What is it?
The Knot explains that wedding insurance “protects a couple's investment from circumstances beyond their control and reimburses expenses incurred.” It can help protect you from problems with “the site, weather, vendors, key people, and sickness or injury” .
What exactly can it cover? 
- Location - Any damage or inaccessibility to the ceremony site due to the building going out of business or closing down is covered.
- Climate - Covers costs of rescheduling the wedding and other details like the flowers, tent rental, and food if weather conditions prohibit anyone in the immediate wedding party or the majority of the guests from attending the ceremony.
- Vendor - If an essential caterer or officiant can't make it, it covers the costs or rescheduling or postponement.
- Illness or injury - Covers unexpected sickness or injuries of the essential wedding party.
- Occupation - If military or job relocation demand immediate action and you need to postpone the wedding, you would be covered.
What does it NOT cover? 
- Cold feet - If you change your mind, you won't get any coverage.
- Jewelry - Watches, jewelry and precious gems might not be covered. Wedding rings might be covered, but most likely engagement rings will not be.
When should you get it?
Although most insurance companies have restrictions on how far in advance you can buy your insurance, you should look into getting your coverage as soon as you can.
What does it cost?
The basic cost is $155 to $550 depending on what kind of coverage you want .
Should you get it?
Whether or not you should get wedding insurance depends on a couple things. Before you make any purchases, you need to check and see if the venue you're booking offers any sort of insurance. If it does, look into what all it covers to determine if you need more coverage. Next, there might be items that you can charge to your credit card to receive similar insurance-like benefits. Under the Fair Credit Billing Act, you are allowed to dispute billing errors, including goods or services that you didn't accept or weren't delivered as expected. This means that “if you are unsatisfied with the quality of the goods or service, and aren't able to get satisfaction from the merchant, most credit card issuers will investigate, and may step in on your behalf and charge a purchase back to the vendor” . Things that your credit card company might be able to dispute include deposits, wedding planner fees, services you expect to receive on the day of your wedding, the dress, anything you buy online, and travel expenses for you and your guests . Check with your credit card company to figure out exactly what they could help you with.
 Wedding Insurance 101, The Knot
 6 wedding expenses you should always charge on credit, CreditCards.com