Explanation
To include a grid or form in an admin page layout using the UI Component, a developer should use the following code:
<referenceContainer name="content">
<uiComponent name="Vendor_Module::ul_component/example_listing.xml" />
</referenceContainer>

Explanation
The preference element in di.xml allows specifying a custom class that will be used instead of the original class when creating an object1. This can be used to override a core class method by extending the original class and overriding the method in the custom class1. The rewrite and argument elements are not valid for overriding core class methods in di.xml1.

Explanation
The read-only core file system in Adobe Commerce Cloud means that the core files of the Magento application cannot be modified. This significantly reduces the number of attackable surfaces on the website, making it more secure.