Is it http:// or https://; both are there; How? Why?

HTTP stands for Hyper Text Transfer Protocol.

The primary difference between http:// andhttps:// is security. 

The S (big surprise) stands for "Secure."
This is why you never ever enter your credit card number in an http website!

If you visit a website or web page, and look at the address in the web browser, it will likely begin with the following: http:///.
This means that the website is talking to your browser using "unsecured" language which means it is possible for someone to "eavesdrop" on your computer's conversation with that website. If you fill out a form on the website, someone might see the information you send to that site. 

But if the web address begins with https://, that basically means your computer is talking to the website in a secure code that no one can eavesdrop on.

If a website ever asks you to enter your credit card information, you should automatically look to see if the web address begins with https://. 

If it doesn't, you should NEVER enter sensitive information... such as a credit card number, SS #, etc.

One Good Samaritan cautioned me through his forwards. I thought I can share with my friends. If you know this kindly add some more information in your feedback.

PLEASE PASS IT ON (You may save someone a lot of grief)!