Why are there many distributions of Java?

Java was first released as proprietary software. In 2006, Sun Microsystems created an open source version of Java called the OpenJDK with a GNU General Public License allowing developers to change and share the program. Sun (and later, the new owner, Oracle) retained Java-related intellectual property and copyrights.

One way to describe Java is to state that only JDKs and runtimes are considered Java if they pass an extensive suite of tests called the Technology Compatibility Kit (TCK). While Java was designated open source, initially, TCK was not. It needed to be licensed, for a fee, from Oracle. This resulted in very few companies making their own branded version of Java.

Today, however, it is possible to get access to the TCK without paying a fee. You have to make a formal request to Oracle, along with presenting several supporting documents explaining why you require access to the TCK. A screening committee will review your request and decide whether to grant you access to the TCK. At the time of writing, 27 organizations have signed the OpenJDK Community TCK License Agreement (OCTLA) and have access to the TCK.

So, why do companies still distribute their own branded version of Java? The simplest answer is to provide support to clients who wish to use Java in situations where the distributor may have more experience in a particular domain. Cloud providers such as Microsoft and Amazon have their own branded versions of Java that have been optimized for their cloud infrastructure. BellSoft, the distributor of the Liberica distribution, is one of the leaders involved in ARM versions of Java. While it might not make much of a difference which distribution you choose, the distribution your clients will use is significant.

Regardless of the distributor, the language is maintained by Oracle. A well-established process allows anyone to propose changes to the language. Through the Java Community Process (JCP), all changes, additions, and removals from the language are carefully reviewed.

The actual coding of changes to the JDK is primarily the responsibility of developers working for Oracle. Consider joining the JCP to keep abreast of changes and contribute to the language.

Let's move on and look at which version you should use since you do not have any experience with the language.