Email notification for Application and tiers

Hi

I define a custom App in custom UI called MyApp including 2 tier called first_tier and second_tier

first tier has 1 VM and the other has 4 VM.

in emailFlter.xml i have defined(for first tier):

....

<Conditions>
  <condition type="Application">MyApp</condition>
  <condition type="Tier">first_tier</condition>

    <condition type=Level">Critical</condition>
</Conditions>

My question is about  below default configuration in emailFilter.xml

<Conditions>
   <condition type="ResouceKind">open_API: demo</condition>

   <condition type ="status">cancel</condition>
   <condition type="Tier">online trading:network</condition>

</Conditions>

can you explain what is relationship  betwen 2 hight light condition ??