Question: its showing below details while checking 'java -version' in CMD

java version "11.0.15" 2022-04-19 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.15+8-LTS-149)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.15+8-LTS-149, mixed mode)

I am getting below response in Eclipse while using 'System.getProperty("java.version")'

Java Version is: 17.0.2

Answer: 
The CMD uses the `PATH` environment variable to search for executables (`java.exe`). The executable is searched in the directories listed in that variable, in the given order. The first one found, is the one that is executed.

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Eclipse uses its own settings:

1. the JRE used to start Eclipse *can* be specified in the `eclipse.ini` file; if not specified there, the OS default will be used (usually the same as the CMD, see above);
2. the JRE used to execute an application inside Eclipse, is specified by the Run/Debug configurations (`Run`-`Run Configurations...`/`Run`-`Debug Configurations...`), the respective project properties (`Project`-`Properties`) and Eclipse preferences (`Window`-`Preferences`-`Java`-`Installed JREs`).
When I chose "Use Default Workspace JRE" inside Java Build Path->JRE System Library it is showing Java 11.0.15 in eclipse