What does it mean when a male dog bites a female dog's neck?

I have two dogs: a Schnauzer and a terrier mix. The terrier mix is a male and the other is a female. Are dogs playing when they bite the other's neck? I mean it's not aggressive or anything but I am just wondering. Is it a sign of dominance?

As you probably know, dogs are related to wolves.In the wild, wolves will hold each other firmly by the neck, without actually hurting eachother to test the trust between them, the dog that is biting the neck is testing how much the dog it is holding trusts him, if the female does not trust him, she would struggle immensly and probably bite back.The female might even do the same back to the male, get him by the neck to see if he trusts her as she trusts him.It's not really dominance, just a test of the trust they have for eachother.Hope that makes sense!

yes its a sign of dominance they are playing/ practicing