Here are the big boys. 3 compartment sinks are very often used as a fully-sufficient dishing-washing method, whereas with a 1 compartment sink or 2 compartment sink you would need to supplement the washing process with a commercial dishwasher. Instead, with a 3 compartment sink, you're able to rinse, wash, and sanitize all with one commercial sink.
The fist compartment, or "tub" or "pot", can be used for your rinsing. This is just to get all the major food, debris, and gunk off of the dishes, pots, pans, etc. Then in the second compartment you will wash the dishes. You do this by putting them into a detergent solution, which is going to get rid of a lot of the grease, and get rid of anything else you missed on the first rinsing stage. Finally, you move the dishware into the third compartment, which is where you do your sanitizing. You will have to submerge the dishes into a solution, which is going to get rid of the rest of the bacteria. (This is the necessary third step that 1 and 2 compartment sinks can't really do well.) In that third, sanitizing step, you should be using hot water, which is actually going to make your dishes dry a lot faster.
Now, that being said, some restaurants will just want a 3 compartment sink for rinsing and washing, and they'll use a commercial dishwasher for the sanitizing stage. It really depends on your workflow and how much space and time you have. Obviously, washing dishing by hands can save you some money when it comes to energy costs, but it will also take more time. And because time equals money, especially when you're paying your employees, sometimes it might not save you money. That's called a paradox. What we're trying to say is this: there's no ONE way to wash your dishes. You'll have to figure out the best start-to-finish process for your own restaurant.
One thing we will say though is this: you can't just wing it! Health code laws in Canada are pretty strick, so you're going to have to make sure you're complying with the bylaws about making sure your dishes are sanitary for your customers.
One addition to a 3 compartment sink that a lot of people like to have are drainboards. Having drainboards on both sides of your 3 compartment sink can give you a place to put your dirty dishes (on one side) and then your clean dishes to dry (on the other side). Or you could choose to have drainboards on just the left or just the right -- up to you!
All of these compartment sinks are high quality, commercial sinks, so they should be able to withstand the wear and tear of nearly any commercial kitchen. But it's worth taking a look at the construction and stainless steel type to ensure you're going to be getting the right sink for your place.
Also, there are a few fancy varieties of 3 compartment sinks. If you want to have all the benefits of a three compartment sink, but don't have the space, try a space saver 3 compartment sink. They have tinnier compartments, so you won't be able to do big pots and pans, but the minimal space can really help out. There are also corner 3 compartment sinks, which are nice if you've got a corner to fill up!
If you're not sure which 3 compartment sink you should buy, just give us a call and we'd be more than happy to help you out. We ship these all across Canada, so we would love to help you buy the right one!