A properties file stores configuration data as key-value pairs that can be parsed by the java.util.Properties class. The document discusses different ways to configure properties in Mule, including using property placeholders, system properties, environment variables, and the mule-app.properties file. It provides an example of configuring a property in mule-project.xml and observes that properties in mule-app.properties take highest priority, followed by global variables, runtime arguments, environment variables, and other property files in alphabetical order.

2.  A properties file is a simple collection of key-value pairs that can be
parsed by the java.util.Properties class. They are often used to store
configuration or localization data. In mule properties file can be
configured using property placeholders and system properties.
 Example of a property file is as below:

3. System Properties:
The placeholder value can come from a JDK system property. If you
start Mule from the command line, you would specify the properties as
follows:

5. Environment Variables:
There is no standard way in Java to access environment variables. But
the setting of environment variables can be done in the run
configurations window…choose Environment tab.

6. Mule-app.properties:
The property can be configured in mule-project.xml as below:
Add an environment variable by pressing the button:

8. Example:
 The example above tries to display the property name which is a
common property from various sources the observation is as below:

9. Observation:
 The property in the mule-app.properties is prioritized the most,
Global variables is prioritized the next most and next is the run time
arguments followed by Environment Variables and then follows the
property files in alphabetical order.

10. Thank You All