They seem the same. Is there a significant difference? I think I am missing something.
A regular trigger only responds to dependency properties.
A data trigger can be triggered by any .NET property (by setting its Binding property). However, its setters can still target only dependency properties.
Another difference is that a DataTrigger can be bound to another control, a StaticResource, etc etc.
<Style TargetType="TextBox">
<Style.Triggers>
<DataTrigger
Binding="{Binding SomeProperty,
ElementName=someOtherControl"
Value="Derp">
<!-- etc -->
You can only examine the instance on which the style is set when using a Trigger. For example, a Trigger applied to a Button can inspect the value of IsPressed, but it would not be able to inspect the (for example) Text value of a TextBox on the same form if you wished to disable the Button if the TextBox was empty.
The short answer (as I'm about to sleep)- A trigger works on dependency properties (typically GUI properties) whereas data triggers can be triggered by any .NET property (typically a property in a ViewModel that implements INotifyPropertyChanged).
来源：https://stackoverflow.com/questions/6499124/whats-the-difference-between-a-trigger-and-a-datatrigger