It is file which describes which files should be written into the exe with XML format.
Take a look on the structure. For example:
<RCC>
<qresource prefix="/">//your prefix
<file>description.txt</file>//txt file
<file>SolarSystem.qml</file>//source
<file>images/earth.png</file>//pictures
<file>images/jupiter.png</file>
<file>images/logo.png</file>
<file>images/mars.png</file>
<file>images/mercury.png</file>
<file>images/neptun.png</file>
<file>images/saturn.png</file>
<file>images/sun.png</file>
<file>images/uran.png</file>
<file>images/venera.png</file>
<file>images/icon.png</file>
</qresource>
</RCC>
So it can be importamt.