What is a Zip Code?

okay, so i wrote the name of the person i sent the mail to and the correct address, city and correct state but the zip code was wrong. i accidentally wrote 94208 instead of 92408. will that affect the mail at all? i wrote everything else correct except...

I want to mail a letter to my friend in Japan for his birthday. I have his house address, but he never gave me his zip code...will the letter still be able to get to him if I only put his house address on the envelope? Or, do you need to have a zip code...

billing zip code zip code

i want to about zip code for england some time we enter the detail then they ask about zip code if we entered post code why it is not vaid they want zip code

I am trying to determine what is the average area square of a zip code in the united states. E.g., are most zip codes in cities/towns in the US 3 miles square? How are zip codes determined in the US?

Hi, I'm trying out for a contest and they want to know my zip code, First i have no idea what a zip code is and second what is my zip code? I live in Canada, Ontario. Please let me know what mine is. Thanks. :)