Example explanation:

Triggers (trigger):
parentTrigger: Defines animations for the parent element.
childTrigger: Defines animations for the child elements.

States (state):
parentTrigger: Has the states start and end.
childTrigger: Has the states visible and hidden.

Styles (style):
Defines final and intermediate styles for different states and transitions.

Transitions (transition):
Defines how the animation should occur between states.

Animate (animate):
Defines the duration and timing function of the animations.

Keyframes (keyframes):|
Used in the transition from visible to hidden in the child elements to create detailed intermediate animations.

Group (group):
Used in the transition from start to end in parentTrigger to animate multiple properties in parallel.

Sequence (sequence):
Used in the transition from end to start in parentTrigger to animate multiple properties in sequence.

Query (query):
Used in the transition from hidden to visible in childTrigger to select and animate child elements.

Stagger (stagger):
Used with query to apply a delay between the animations of the child elements, creating a cascading effect.