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Educational content

What is a blockchain?

A blockchain is a digital register of data contained in different blocks chronologically linked to each other.
Peer-to-peer transactions take place within a network of nodes that can be distributed in a decentralised way around the world.

What is Mainnet & Testnet?

A testnet (Test Network) is an experimental network where developers can create, test, modify functionalities and monitor the blockchain network performance.
A mainnet (Main Network) is the stable version of the blockchain.

What is a Hard fork?

A hard fork is a software update performed by the nodes of a blockchain.
Unlike soft forks, which provide backward-compatible updates, a hard fork will render the old protocol (which defines the rules) of the blockchain incompatible and the blockchain will cease to be used.
However, a lack of consensus within the community may result in the community splitting into two separate blockchains.
Each node keeps a copy of this digital register of data and contributes to the proper functioning and security of the network.

What are the different types of cryptocurrency?

In 2021, there are more than 10,000 cryptocurrencies.
Among them are coins and tokens.
A "coin" is the native cryptocurrency of a particular blockchain, i.e. its own network.
A token is supported by a third-party blockchain.
Sending tokens requires a certain amount of that third-party blockchain coin to pay the transaction fee.

What is Bitcoin?

Bitcoin is an open source peer-to-peer transactional technology (announced in 2008 and launched in 2009 by an unknown person or group of persons using the alias Satoshi Nakamoto) operating with no middle-men: no central authority/bank.
The protocol fixes Bitcoin’s max supply at twenty-one (21 000 000) million bitcoins.

What is Ethereum?

Ethereum is a decentralised exchange protocol that also allows users to create searchable and applicable smart contracts.
The native coin of the Ethereum chain is Ether (ETH).

What is an ERC20 Token?

An ERC20 Token is an asset supported by the Ethereum blockchain.
Sending ERC20 tokens requires a certain amount of Ether (ETH): the native coin of the Ethereum blockchain.

What is an NFT?

Unlike a standard token, a non-fungible token (NFT) is a token that is not interchangeable (unique TokenID).
An NFT most often represents an image but can also represent a video or an audio file.

What is a dApp?

It is a computer application that runs on a decentralised computer network.
Some famous examples are decentralised exchanges (DEX) such as :
  • ​THORSwap (World's First Multi-Chain DEX Powered by THORChain)
Example of cross-swap : ETH - BTC
Uniswap homepage
PancakeSwap homepage
SushiSwap homepage
  • ​1inch (Ethereum, Polygon & Binance Smart Chain (BSC)-based)
Example of Ethereum swap : ETH - MTA
Example of Ethereum swap : ETH - LINK
But also NFT platforms such as :
  • ​OpenSea (Ethereum & Polygon-based)
Presentation of OpenSea
Rarible homepage
  • ​Refinable (Binance Smart Chain (BSC)-based)

What is a Smart Contract?

These are contracts that rely on blockchain technology to make the terms and conditions of their execution unforgeable.

What is Gas?

Gas in crypto refers to the computational effort required to execute a transaction (TX).
You have to pay a gas fee, with the native coin of the blockchain/network used, in order to send an asset or execute a smart contract.
These fees are paid to the miners who spend resources (computing power and electricity) to verify and process your transactions.

Transaction (TX) fees on Ethereum

1 Gwei = 0.000000001 ETH
Units of gas (gas limit) = the maximum amount of computational resources that can be utilised to complete the TX
1 unit of gas is worth x amount of Gwei
ETH TX fee = number of gas units * price (in Gwei) of a gas unit

What is a Nonce?

A nonce is a variable that increments by 1 at each outgoing transaction made and thus represents the total number of transactions made with a specific address.
  • On the Etherscan blockchain browser, you can view nonce by clicking on Click to see More
  • The first value corresponds to the Transaction Nonce
  • The second value corresponds to the Index position of Transaction in the block

What is an airdrop and why they can be dangerous?

Airdrops are distributions of digital assets to the public by virtue of holding a certain token or simply by virtue of holding an active address on a particular blockchain.
However, if you receive airdropped tokens / NFTs on one of your XDEFI Wallet addresses but don't know about these crypto assets or why you received them, DO NOT interact with them.
Sometimes these are harmless promotional airdrops, but they can also be phishing attempts to trick the user into interacting with their wallet (sometimes by displaying real wallet data on a fraudulent website) in order to take away funds.
This happens mainly on Ethereum or Binance Smart Chain (BSC) addresses but can happen on any chain (and with addresses generated by any wallet provider).
So DO NOT try to send/sell/swap these crypto assets.
The only way to avoid seeing these tokens is to not add them to your main screen or create a new wallet or account (but this does not guarantee that this new wallet or account will not receive suspicious tokens in turn).
  • Have a safe web browsing experience and double-check the URLs you visit.
Be aware that a fraudulent site address may start with https (with a lock icon). The lock doesn't tell you anything about the legitimacy of the website. The only thing it means is that the website sends and receives information from your web browser via an encrypted connection.
  • Don't interact with unknown airdrops.

What is KYC?

The Know Your Customer (KYC) guidelines in financial services require professionals to make efforts to verify the identity of their customers. This is part of a bank's or an organisation's wider anti-money laundering (AML) policy.