When can you take your dog to the dog park and why is it good for dogs to go there?

[debbie]

I am debating on taking my puppy (8 month old beagle) to the dog park. Is he off the leash in there? I'm afraid I'd have to chase him around. Why is it good for dogs to go there?

 

[Houndly]

It's good so he can socialize with other dogs, and other people too.