My dog loves dog bisquits. I give them to her throughout the day. They are the hard and dry type. 
Awww! That's cute! Do you give them to her as a reward for doing something specific, like a trick?
When she was younger I did. Now it's more as a dietary supplement and a snack, like us humans. 
I'll bet she loves that! Do the bisquits have vitamins and other health benefits?
I am not sure, but, the biscuits are supposed to help clean the dog's teeth, promoting oral health. 
That's certainly an added benefit! It's very hard to brush a dog's teeth! Can you recommend a good brand of biscuits?
No, but just make sure it's not dog's bread. It's a special bread made with ground glass, poison and needles intended to kill dogs.