Postal Letter

What's the difference between usps priority mail international vs first class mail international?

I wana send a very small box to uk and I was looking at the usps site and I saw 2 options for sending the package..

Public Comments

1. USPS Priority Mail International gets there a little faster and is relatively more expensive than First Class Mail. First class mail have weight limits, [I think the limit is under 12 ounces for International]. It'd be cheaper and would take a few days longer (on average) than Priority.
2. Go for the first class if your package is under four pounds. It will be significantly cheaper and take only a day or two longer. Make sure you include a short customs form on it.