The default-java folder is a symbolic link to the actual location of the JDK install on Ubuntu. When you reference the JDK install location in applications or in environment variables such as ...

When using Environment Variables to switch Java versions through JAVA_HOME, updating PATH with %JAVA_HOME%\bin works in CMD, but does not work in PowerShell, because ...

With each new Java platform release, the stewards of the language always include a few new preview features that can be toyed with only if a developer knows how to unlock the capabilities at runtime.