Question: Is there any difference between how GET/POST works while in HTTP or HTTPS protocols?
What is visible in HTTPS GET/POST packet when you try to sniff the data? host IP? domain name? full GET request? 
What information TLS hides after successful handshake?

I can't seem to close this knowledge gap by looking in the internet, there's just no such question asked.

Please advice, make it reference for the internet.

Answer: 
1. URL begins with “http://" in case of HTTP while the URL begins with “https://” in case of HTTPS.
2. HTTP is unsecured while HTTPS is secured.
3. HTTP uses port 80 for communication while HTTPS uses port 443 for communication.
4. HTTP operates at Application Layer while HTTPS operates at Transport Layer.
5. No encryption is there in HTTP while HTTPS uses encryption.
6. No certificates required in HTTP while certificates required in HTTPS.
The entire request , and the response as well is encrypted for https. A middle man doing a [Man in the middle attack](http://en.wikipedia.org/wiki/Man-in-the-middle_attack) , can only get the destination host and port, by intercepting.

This [Google Answer](http://answers.google.com/answers/threadview/id/758002.html#answer) explains it properly. To quote

`HTTPS Establishes an underlying SSL conenction before any HTTP data is
transferred. This ensures that all URL data (with the exception of
hostname, which is used to establish the connection) is carried solely
within this encrypted connection and is protected from
man-in-the-middle attacks in the same way any HTTP data is.`

In terms of the TCP/IP stack, HTTP, an application layer protocol, uses TCP layer security. First , a secure TCP connection is established, then only the request is sent and response received.