The holidays are approaching, and that means the United States Postal Service’s yearly initiative, Operation Santa, is back in business. Here's what to know.

Starting on Nov. 18, the letters will be available online for anyone to read and hopefully grant the wishes contained in them. To adopt a letter, you create an account on the Operation Santa website. After you read them and select who you want to help, you buy the gifts and ship them.

The United States Postal Service has also been fulfilling the holiday wishes of children across the country for over a century. For 112 years, Operation Santa - a program run by the USPS - has encouraged members of the public to "adopt" a wishlist and donate toys to children in need.