Each one has a slightly different macOS installer. Some are .pkg files that write to /Library/Java . Some are .tar.gz that you manually place in /usr/local . No matter which JDK you download, macOS has multiple Java versions lurking. Apple even ships a legacy 1.6 stub in some systems (don’t ask).
Wait, what? Java is free, right?
Because Step 1: The Oracle of “Free” You Google “Java 21 download mac” . First result: oracle.com/java/technologies/javase/jdk21-archive-downloads.html . java 21 download mac
But Rosetta 2 is translating every bytecode instruction like a sleepy interpreter. Your shiny ARM CPU is pretending to be an Intel chip from 2019. Each one has a slightly different macOS installer
Now go write some virtual threads and pretend the last 25 years of Java complexity never happened. P.S. If someone tells you “Java is dead,” show them this article and the 500MB of JDK downloads happening every second. No matter which JDK you download, macOS has
Buried in legalese: “For development use only. No production. Also, we may audit you.”