Facebook offers is a feature which allows users to get discounts from businesses, whenever they post an offer on their Facebook page. Initially it was described as 'a free and easy way for businesses to share special discounts and promotions that let a business share a discount or promotion directly from a Facebook page'. But now these offers require a budget to run.
Depending on how businesses use offers, this is a very useful feature on Facebook. If you are one of those who haven't used it yet and want to explore it, here's a complete guide on how to run all three kinds of Facebook offers: In Store only, In Store and Online, and Online only.