Understanding Log4j: What are Loggets and How to Use Them

Log4j is a Java logging framework that allows you to write logs in your application. Log4j provides a way to configure the logging settings for your application, such as the level of detail that should be logged, the format of the log messages, and where the logs should be stored.

Loggets are the actual log messages that are written to the log file by your application. They can include information such as the time and date of the message, the source of the message (e.g., a specific class or method), the level of the message (e.g., debug, info, warn, error, etc.), and the message itself.

For example, if you have the following log4j configuration in your application:
```

```
And you have the following code in your application:
```
Logger logger = LogManager.getLogger("myLogger");
logger.debug("Starting up the application");
```
Then the log4j configuration will cause the message "Starting up the application" to be written to the log file with a debug level, and the format of the log message will be "2018-01-01 10:30:00,000 [main] debug myLogger - Starting up the application".

So in this example, "Starting up the application" is a logget.