Differences between TLS 1.2 and TLS 1.3

With the release of TLS 1.3, there are promises of enhanced security and speed. But how exactly do the changes from TLS 1.2 to TLS 1.3 cause these improvements? The following is a list of differences between TLS 1.2 and 1.3 that shows how the improvements are achieved.
 
wolfSSL is among one of the first libraries to support TLS 1.3. Below are the major differences between TLS 1.2 and TLS 1.3

TLS 1.3

This protocol was defined in an Internet Draft in April of 2017. TLS 1.3 contains improved security and speed. The major differences include:

• The list of supported symmetric algorithms has been pruned of all legacy algorithms. The remaining algorithms all use Authenticated Encryption with Associated Data (AEAD) algorithms.

• A zero-RTT (0-RTT) mode was added, saving a round-trip at connection setup for some application data at the cost of certain security properties.

• All handshake messages after the ServerHello are now encrypted.

• Key derivation functions have been re-designed, with the HMAC-based Extract-and-Expand Key Derivation Function (HKDF) being used as a primitive.

• The handshake state machine has been restructured to be more consistent and remove superfluous messages.

• ECC is now in the base spec  and includes new signature algorithms. Point format negotiation has been removed in favor of single point format for each curve.

• Compression, custom DHE groups, and DSA have been removed, RSA padding now uses PSS.

• TLS 1.2 version negotiation verification mechanism was deprecated in favor of a version list in an extension.

• Session resumption with and without server-side state and the PSK-based ciphersuites of earlier versions of TLS have been replaced by a single new PSK exchange.
 
Internet Draft: https://tools.ietf.org/html/draft-ietf-tls-tls13-20
 
Resources:

If you would like to read more about SSL or TLS, here are several resources that might be helpful:

TLS – Wikipedia (http://en.wikipedia.org/wiki/Transport_Layer_Security)
SSL versus TLS – What`s the Difference? (http://luxsci.com/blog/ssl-versus-tls-whats-the-difference.html)
Cisco – SSL: Foundation for Web Security (http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_1-1/ssl.html)