Java JDK
is the first thing you need to install before starting to try something. There are several JDK editions, but you must install version 17 in all cases.
OracleJDK
:1 This version was free until Java 11. After this version, you can use it for development/test environments, but you need to pay a license to use it in production. This version of the JDK offers the most recent patches of bugs and new features because Oracle is the owner of the language.
OpenJDK
:2 When Oracle bought Sun Microsystems ...