COD stands for cash on delivery, and that means exactly what it sounds like. Basically, this means that the courier service that is used to deliver whatever the package may be, will accept payment at the time of delivery. You may be able to find a Chicago courier service that offers this option, if you look around a bit. It's also important to note that COD usually doesn't mean literal cash. You should be prepared to make payment with a check or money order at the time of delivery. Also, make sure the payment is made out for the exact price shown on the invoice.
COD takes on a slightly different meaning when you are dealing with large commercial freight shipments. In this case, it stands for collect on delivery. It's not as confusing as it might sound; it basically means the same thing as cash on delivery. These options are convenient, because you might end up doing business with a company that will only deal in COD deliveries. There is some risk involved in the area of COD deliveries. When you approve this type of delivery, you are trusting that the payment will be made, and in the full amount. There is always the possibility of someone refusing to pay when they receive their shipment.
There can also be some benefits that come from COD deliveries. For example, it is a good way for a courier service to build a trusting relationship with companies that use them for shipping. The company selling the products will appreciate the fact that you have such confidence in them. This is how solid business relationships are formed, through a mutual trust and respect. This can go a long way in generating future business with that company and others as they recommend you.
You can find out if a courier service offers COD deliveries by logging onto their website. There, you can usually find this information, and much more. You may also have to just pick up the phone and call them to gain the information that you need. Some couriers will offer this service and some will not. Usually it depends on the type of experience they have had dealing with it in the past. Sometimes a courier will only offer COD deliveries after you have proven that you are a trustworthy client. Sometimes it takes a while, and a lot of business to make this happen.