The most well-known JDK and primary source of Java11 is Oracle.
OpenJDK: JDK 15, JDK 14, and JMC Azul Systems are available for use. Zing is quick and effective. OS JDK for Linux
Zulu-based Azul Systems offers products for Linux, Windows, and Mac OS X.
AIX, Linux, Windows, and numerous other OS supported by IBM J9 JDK

Standard Edition Java Platform. Enterprise Edition Java Platform. Micro Edition Java Platform.

The Java Development Kit is an implementation of one of the Java Platform:

• Standard Edition (Java SE),
• Java Enterprise Edition (Java EE),
• Micro Edition (Java ME),