After and Before Targets

Means. targetA will run after TargetC.

<Project xmlns="...">
<Target Name="TargetA" AfterTargets="TargetC">
 <Message Text="This is Target A" />
</Target>
<Target Name="TargetB">
 <Message Text="This is Target B" />
</Target>
<Target Name="TargetC">
 <Message Text="This is Target C" />
</Target>
</Project>

This behaviour invokes that, when targetC is ran with /target:C option or through any other option, TargetA will run after that.

But it doesn't mean, C will run before we run A(when A is invoked).That is dependson.

<Project xmlns="...">
<Target Name="TargetA" AfterTargets="TargetC">
 <Message Text="This is Target A" />
</Target>
<Target Name="TargetB" AfterTargets="TargetC">
 <Message Text="This is Target B" />
</Target>
<Target Name="TargetC">
 <Message Text="This is Target C" />
</Target>
</Project>

This will run in order, C A B, hen we invoke C.

<Project xmlns="...">
<Target Name="TargetA" BeforeTargets="TargetC">
 <Message Text="This is Target A" />
</Target>
<Target Name="TargetB" AfterTargets="TargetC">
 <Message Text="This is Target B" />
</Target>
<Target Name="TargetC">
 <Message Text="This is Target C" />
</Target>
</Project>

This means, when C invoked, order: A C B

Indirect invocation can be altered with conditionals.As value is false, C will not be invoked after A.

If it is a string instead of boolean, Condition="$(DoIt) == 'foo'"