So what is a dog crate?
A dog crate can be a foldable metallic fence, plastic dog house, collapsible plastic or foldable portable nylon mesh crate. You will need to choose one that is appropriate for your dog depending on where you intend to put the crate.
There are different sizes of crates to suit the different breeds of dogs. Your dog must be able to sit upright inside the crate and lie down comfortably across the crate. It must be able to turn around inside the crate.
I have two crates for my Corgi dog; a collapsible metallic fence where I put her in the car porch if I have visitors or when she has her meals, and a heavy duty plastic crate when I have to move her indoors at night. My other Beagle dog just uses another heavy duty plastic crate and he is outdoors throughout the day and night.
When I first have my puppy Beagle, I bought a large size crate that allows the top to be removed and have a gate too. I have the puppy sleeping inside the crate and put a towel there for its comfort. I removed the top and played with the puppy inside the crate so as to get the puppy used to it. The puppy only slept inside the crate at night and was allow moving about the garden during the day. The puppy learned that the crate is its home or den and would not soil it.
Importantly, I do not believe in putting the puppy inside the crate for too long other than his sleeping hours at night. The crate should not be used for confinement as a punishment for some wrongdoing. For example, it should not be use to punish your dog when it does not listen to your commands during training.
Unfortunately, there are owners that are putting their dog inside the crate when they leave for work as they fear that the dog may destroy the home furnishings and soil the carpet, especially if they are living in an apartment. If you do not have a choice, then I hope you can get a reasonably big crate so that the dog have sufficient room to move around and one that have enough ventilation holes ( I actually drilled more holes in my dog crate so that it is better ventilated as the weather is sunny throughout the year ). Hopefully, you do not work late most of the time so that its confinement is limited to no more that six to eight hours. Upon your return home, let the dog out immediately and walk the dog so that it can stretch and ease itself.
My beagle grew up with the same large size crate that I bought together with it. The crate can last for years as long as you take good care of it and clean it regularly too. My beagle is so used to this crate that it still likes to go inside it for a nap even though I have gotten a much bigger crate for him recently. My two dogs love their crates placed in the car porch, and use them as their own dens, whether for resting or to hide from the thunder and lighting when there are any thunderstorms.