A discount code is very simply a code that is given to you in order to give you a discount on a particular item or at a particular store. A very simple explanation and one which only really tells you the absolute basics which most of us already know. Actually, discount codes come in a variety of different types and styles and can be used in different ways.
Personal Discount codes are codes given specifically to one individual. They can only be used by that person, and can't be shared with others or used on a different account. Discounted Stamps These codes can only be used once.
One off Discount codes are slightly different from Personal Discount codes, as they can only be used once, but can be used by anyone, and not just the individual who was given the code, meaning that if you receive one of these and can't use it, but know someone who could, then you could pass the code to them, and they could use it instead of you. Being one off codes, you couldn't use it and then pass it on to someone else as it would only work the first time used.
Once per account codes - these codes are the sort you will often find listed on websites who share this sort of information as they can be used by anyone, but can only be used once PER ACCOUNT or PER INDIVIDUAL or PER HOUSEHOLD. I'm noting these three as different because they are. A per account code can be used once on each account, and if you as an individual have more than one account, you could use this code on each one without a problem. If the code is once per individual then you could use it, and your partner living at the same address could use it on their account, but you couldn't use it on multiple accounts in the same name. One that states it's for use per household, would mean you could use it on your account, but if you did, then your partner living at the same address couldn't use it as well, but someone else living at another address could do so.
Voucher shopping codes are also sometimes a bit specific in what you can use them FOR. They might be usable to get you a certain amount off anything on the site, but only when you spend over a certain amount. Alternatively there might be no minimum order value (mov) which means that if you can find something to the value of the voucher or below it, then you can order it for nothing - or if the site charges postage, then just for the cost of the postage. These vouchers which have no mov and which can be used by anyone on any account are usually the most highly sort after type of discount code, and even more so if the site offers free postage and has items for sale that are to the value of or below the value of the amount of the code. One recent example of this was a code given out by play.com for £2 - play doesn't charge for postage, and there was no mov on the codes. They were however limited to one per household. Some people managed to find cds and dvds for £1.99 meaning that they didn't have to spend anything to get the item, and therefore it was free to them.