Django ORM Q объект

Question

В чем разница между:

books = Book.objects.filter(name__in=names,film__isnull=True)
books = books.union(Book.objects.filter(name__in=names,film__date__lte=date)).distinct("id")

VS

from django.db.models import Q
books = Book.objects.filter(Q(name__in=names),Q(film__date__lte=date)| Q(film__isnull=True)).distinct(id)

и разницей между:

[...].filter(
    Q(hide=False) & Q(deleted=False),
    Q(stock=False) | Q(quantity__gte=1))

VS

[...].filter(
    Q(hide=False),Q(deleted=False),
    Q(stock=False) | Q(quantity__gte=1))

thx