How do trait properties and static properties behave when a trait is used by multiple different classes, and is that state actually shared between them?

A trait can define its own properties, including static properties, and when a trait is used by a particular class, that trait's properties effectively become properties of that specific class, meaning each individual class using the trait gets its own separate, completely independent copy of any regular instance properties, while a static property defined within a trait is shared only among instances of that same specific class, not shared globally across every different class that happens to use the same trait, which is an important distinction to understand correctly.

trait Counter {
    protected static int $count = 0;

    public function increment(): void {
        static::$count++;
    }
}