Explanation of commonly used terms

If you’ve come across a term you do not know or understand, you can find a list of commonly used terms with their explanations below.

Augmented reality

Augmented reality (AR) connects the virtual and the real world. Using AR technology, you can project a digital image into reality through your mobile phone's camera.


Blockchain is a new kind of (decentralised) database in which transactions can be stored. These can be all kinds of transactions. One case might involve payments with a digital currency; another might involve important data that two parties exchange, such as contracts, diplomas or property deeds. The blocks of information are digitally 'signed' by both parties. Without third party intervention, and they are stored in the database straightaway.


Everyone has a wallet or something you keep money in. Cryptocurrency also requires you to download a wallet. You can download this software for your phone, PC or tablet. There are a number of wallets available on the market, and the most widely used for crypto stamps is Metamask. As soon as you have installed a wallet, you can add crypto currency to your wallet.


NFT is the abbreviation for 'non-fungible token'. Non-fungible means that it cannot be exchanged for anything else. In other words, each token is uniquely identified and cannot be exchanged for other tokens. All NL crypto stamps with the same design form a group on the blockchain and are clearly registered in that way. Each digital stamp image therefore constitutes an NFT.

Smart contract

A smart contract is a computer program that runs on a blockchain. The code is completely transparent, so that everyone can see exactly how it works and how someone is using it. Since the blockchain is immutable, this code cannot be altered retrospectively. This allows users to be sure that these rules will not change in the future either.

Secret word list

On the NL crypto stamp there is a private key/secret word list. You should keep this list of words safe and not share it with anyone. You need it to create your own digital collection or to transfer it when selling. The secret word list becomes visible if you carefully remove the protective film on the back of the stamp at code [2]. Scan the QR code or enter the 'secret word list' at cryptostamp.nl. Keep it in a safe place and do not share it with anyone.


Cryptocurrency is digital money. You cannot physically hold it. Cryptocurrency is registered on a blockchain and you store it in a (digital) wallet.

Gas fees

Gas fees are the transaction costs you pay to the miners to carry out a transaction on the blockchain. You pay these gas fees to store your digital twin in your wallet and to send it to someone else, for example. For the NL crypto stamp you need Polygon.


Polygon (MATIC) is a ‘token’, a cryptocurrency that works through the existing Ethereum network and is easy to use in conjunction with other NFT platforms. It works through a ‘proof-of-stake’ system, which means it processes many transactions per second. Because Polygon processes transactions faster and more cheaply than many other cryptocurrencies, it can continue to grow alongside the ever-expanding world of NFTs.