RESTful Java Web Services - Third Edition

HTTP versions

HTTP has been consistently evolving over time. So far, there have been three versions. HTTP/0.9 was the first documented version, which was released in the year 1991. This was very primitive and supported only the GET method. Later, HTTP/1.0 was released in the year 1996 with more features and corrections for the shortcomings of the previous release. HTTP/1.0 supported more request methods such as GET, HEAD, and POST. The next release was HTTP/1.1 in the year 1999. This was a revision of HTTP/1.0. This version is in common use today.

HTTP/2 (originally named HTTP 2.0) was published in 2015. It is mainly focused on how the data is framed and transported between the client and server. It is currently supported by major browsers ...