what’s the difference between priority mail and first class

what’s the difference between priority mail and first class? Priority Mail and First Class Mail are both services offered by the USPS, but they differ in speed, weight limits, and cost. Priority Mail typically delivers within 1-3 business days, includes tracking and insurance, and allows for heavier packages (up to 70 lbs). In contrast, First Class Mail is typically for smaller, lighter packages (up to 13 oz) and is cheaper but slower, with delivery times ranging from 1-5 business days.