What is the difference between http and https?

Answer 1

HTTP means Hyper Text Transfer Protocol
HTTPS means Hyper Text Transfer Protocol Secure

HTTP is a protocol which used to allow you to communicate with web sites.
HTTPS is a secure extension and information exchanged between you and a web site is encrypted and cannot be hijacked by someone who might want to electronically trap when you type a credit card number, a password, a social security number, or any other person information. There are two common types of encryption layers: Transport Layer Security (TLS) and Secure Sockets Layer (SSL), both of which encode the data records being exchanged.

Default port for HTTP is 80 for http and 443 for https. Except these point HTTPS follows the same HTTP protocols.

Answer 2

HTTP is a system for transmitting and receiving information across internet. HTTP serves as a request and response procedures commonly used to access html pages and other resources. In cases where we are exchanging confidential information like credit card details , bank details etc we need a more secure server in order to prevent unauthorized access , that's where secure HTTP or HTTPS comes into picture. In HTTPS encrypted information is exchanged after ensuring both sides are using the same key. The key is contained inside the public key certificates provided that are verified by a third party so that clients are assured that key is secure. HTTP does not use public key certificates.
Other than this basic difference HTTP uses port 80 as default port where as it is port 443 in case of HTTPS.