Some JDK products are free-of-cost and some require a fee. So your first chore is to choose a vendor and obtain and install a JDK. So you will find the quality and performance to be largely the same across these JDK products. Nowadays, most of these companies’ offerings are based largely or entirely on the open-source code base collaboratively built at the OpenJDK project.

Other vendors include, off the top of my head: Amazon, Azul Systems, Microsoft, Adoptium, SAP, BellSoft, Red Hat/IBM, Pivotal, and maybe more. Oracle Corporation is but one of several vendors providing builds and installers for a JDK.

The first sentence of the linked Wikipedia article on JDK is incorrect in claiming Oracle is the sole vendor. A JDK is composed of development tools such as a compiler, and of runtime tools that include a Java Virtual Machine (JVM) and an implementation of the standard libraries including the classes such as ArrayList, LocalDate, and so on. A JDK is an implementation of the Java™ SE (Standard Edition) specifications.

Eclipse java ee download