The main difference between http and https is all about keeping you secure.
http is a protocol for information to be passed back and forth through web server. The important things is the letter "s" which make difference between http and https.The letter "S" which stands for "secure" If you visit a web site which started http, this means that website talking to your browser is unsecure regular language.This is why you never enter your credit card number in an http website. You should know how much important this!
If a website ask you a credit card information,you will see the site starting with https automatically. Don't give credit card or sensitive information in http site. See details- (*promotional backlink removed*)
Thanks,
Josef,