what does first class postage mean

what does first class postage mean refers to USPS’s most affordable shipping option for sending letters and small parcels that weigh 13 ounces or less. First-Class Mail is a quick and affordable service, delivering in 1-3 business days depending on the destination. It includes tracking for certain packages and offers delivery of cards, letters, and lightweight packages. First-Class Mail is ideal for sending personal mail and small retail orders when speed and cost-efficiency are priorities.