I get confused with the terms in this area. What is SSL, TLS, and HTTPS? What are the differences between them?
TLS is the new name for SSL. Namely, SSL protocol got to version 3.0; TLS 1.0 is "SSL 3.1". TLS versions currently defined include TLS 1.1 and 1.2. Each new version adds a few features and modifies some internal details. We sometimes say "SSL/TLS".
HTTPS is HTTP-within-SSL/TLS. SSL (TLS) establishes a secured, bidirectional tunnel for arbitrary binary data between two hosts. HTTP is a protocol for sending requests and receiving answers, each request and answer consisting of detailed headers and (possibly) some content. HTTP is meant to run over a bidirectional tunnel for arbitrary binary data; when that tunnel is an SSL/TLS connection, then the whole is called "HTTPS".
To explain the acronyms:
SSL VS TLS
The terms SSL and TLS are often used interchangeably or in conjunction with each other (TLS/SSL), but one is in fact the predecessor of the other — SSL 3.0 served as the basis for TLS 1.0 which, as a result, is sometimes referred to as SSL 3.1.
Which is more Secure SSL or TLS
In terms of security they both are consider equally secured
The main difference is that, while SSL connections begin with security and proceed directly to secured communications, TLS connections first begin with an insecure “hello” to the server and only switch to secured communications after the handshake between the client and the server is successful. If the TLS handshake fails for any reason, the connection is never created.
(SSL and TLS vs HTTP)
HTTP protocol is used to request and recive the data and https in which the 's' is nothing but secure SSL which makes the http protocol request and receive activity encrypted so no middle man attacker can obtain the data easily.
If neither SSL nor TLS is used with HTTP
then your connection with the web server is unencrypted all the data will be sent in plaintext any middle man attacker can obtain and view that data.
so should go with SSL or TLS
well, both are same but TLS is more extensible and hoping to get more support in future and TLS is backward compatible.
SSL and TLS are protocols that aim to provide privacy and data integrity between two parties (see RFC 2246), designed to run over a reliable communication protocol (typically TCP). Although the TLS specification doesn't talk about sockets, the design of SSL/TLS was done so that applications could use them almost like traditional TCP sockets, for example
HTTPS is HTTP over SSL/TLS, where the SSL/TLS connection is established first, and then normal HTTP data is exchanged over this SSL/TLS connection. Whether you use SSL or TLS for this depends on the configuration of your browser and of the server (there usually is an option to allow SSLv2, SSLv3 or TLS 1.x). The details of how HTTP and SSL/TLS form HTTPS are in RFC 2818.
Regarding the difference between SSL and TLS, you may be interested in these two answers I wrote for these similar questions on StackOverflow and ServerFault:
Generally, the higher the version or SSL/TLS, the more secure it is, provided you choose your cipher suites properly too (higher versions of TLS also offer using cipher suites that are considered better). (SSLv2 is considered insecure.) In addition, SSL doesn't fall under the IETF scope. For example, the TLS renegotiation fix had to be retrofitted for SSLv3 (although SSL/TLS stacks had to be updated anyway).
You may also be interested in this answer:
Note that some people oppose SSL and TLS as being the difference between "SSL/TLS upon connection" and "upgrade to TLS" (after some conversation using the application protocol). Despite some of these answers being relatively highly upvoted, this is incorrect. This mistake is propagated by the fact that certain applications, like Microsoft Outlook, offer two configuration options called "SSL" and "TLS" for SMTP/IMAP configuration when they really mean "SSL/TLS upon connection" and "upgrade to TLS". (The same goes for the JavaMail library, I think.)
The RFCs that talk about STARTTLS were written when TLS was already an official RFC, that's why they only talk about upgrading the connection to TLS. In practice, if you tweak the configuration of your mail client to force it to use SSLv3 instead of TLS (not something I would generally recommend), it's still likely to be able to upgrade to SSL/TLS using STARTTLS with an SSLv3 connection, simply because it's more about the mode of operation than the version of SSL/TLS and/or the cipher suites.
There is also a variant of HTTP where the upgrade to SSL/TLS is done within the HTTP protocol (similar to