Usually when you pay on Yandex.Money's website, the purchase amount is simply transferred from your Yandex.Money account to your cell phone account, a serivce provider, an online game, etc. But this isn't always the case. Like when you buy a PIN.
A PIN is a secret sequence of numbers that is used to pay for different services (e.g. long distance calls, voice over IP, or Internet service). On pre-paid phone cards that are sold in regular stores, the PIN is located under the scratch-off protection strip. But on Yandex.Money you only buy a virtual version of such a card — just the code itself without any physical medium.
Using a PIN to buy a good or a service involves two steps:
Remember: you can only use the PIN you buy once. So make sure no one else gains access to your PIN before it’s activated.