what is first class mail usps

what is first class mail usps is a type of mail service provided by the United States Postal Service (USPS) that is typically used for sending lightweight, non-urgent mail such as letters, postcards, and small packages. First Class Mail is one of the most affordable services, and it offers delivery times of 1 to 3 business days, depending on the destination. For what is first class mail usps, tracking services are available for packages, but not for letters or postcards unless they are specially endorsed.