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Ethereum Tokens 101

One of the most useful features of Ethereum technology is its ability to host sub-currencies,  known as ‘tokens’, directly on its blockchain. These tokens are each ruled by a smart contract, which self-executes commands based on a unique, immutable code.

There are several different types of tokens on the Ethereum blockchain, and multiple sub-categories exist within those types. We’ll take a quick look at the interesting variations of tokens, and address some aspects of their uses.


The most common type of token launched on the Ethereum blockchain follows the ERC20 standard. ERC stands for ‘Ethereum Request for Comment’, which is basically a development proposal for the framework of the Ethereum blockchain. Ethereum is decentralized, so developers suggest new requests that are either abandoned or accepted by the community – the latter leading to widespread adoption of the protocol.

ERC20 tokens are the kind you see the most frequently. They can be seen as a sub-currency of Ether, each having a pre-specified supply and purpose while still relying on ETH for the gas (transaction fees) they use to deploy the contract. These tokens hold their own value separate from the ETH, and they are generally used for more nuanced purposes. Anyone can build a token on the Ethereum blockchain, and there are many different reasons to do so. For example, there is a token called Maker (MKR) specifically used to manage another token called the DAI stablecoin.

Wait, stablecoin? What’s that?

For an in-depth look at stablecoins, check out our stablecoin explainer article. But the very concise summary is that stablecoins are a sub-genre of ERC20 tokens that maintain the same value, generally tied to a fiat currency like the US dollar. It creates a safe space for investors and those looking to decentralize their financial lives to explore crypto in a less volatile, more familiar way.

Some stablecoins are backed directly by real fiat currencies, some are backed by physical assets like gold, and some are managed by smart contracts to keep the value stable at a predetermined price. DAI, for example, is managed by smart contracts that keep its value at $1 USD. This process allows DAI to remain fully decentralized, while other types of stablecoins have been criticized for using a centralized foundation to maintain their stability.

It’s important to make the distinction that not all stablecoins are ERC20 tokens. Some are full fledged coins on their own blockchains, separate from Ethereum (one well-known example is Tether), and they can’t be stored in an ERC20/ETH wallet.

Tokens Moving to Mainnet

Occasionally a project with an ERC20 token can get too large or ambitious to stay on the Ethereum blockchain. They may want to change the framework of the technology that their currency runs on, or they may just simply want more control over what they can and can’t do. When this happens, the team can decide to transition to mainnet.

This means the team is building their own separate blockchain for the token, attempting to graduate it to a full-fledged coin. It is no longer bound to Ethereum in this case, but instead becomes a currency on a different blockchain. These currencies can not be kept in Ethereum wallets, so generally the token’s team will hold a swap on an exchange like Binance. The exchange takes the ERC20 tokens and swaps them for the new coins which are placed into a different wallet on the new blockchain. It’s important to follow updates on all your token investments to see if they plan to transition to mainnet in the near or far future, since getting left behind could have negative consequences to your assets.


Non-Fungible Tokens, or NFTs, are one of the most brilliant and understated uses of Ethereum technology. Each token represents a single, unique thing. No two NFTs are alike, so holding one proves without doubt that you are the true owner of whatever it represents. Whether that’s a digital collectible character (like CryptoKitties) or the deed to your house, NFTs are ground-breaking for their individualized properties that can be applied to an infinite amount of tangible objects.

The (Possible) Future: ERC223, et al.

In all aspects of life, things change. The Ethereum blockchain is no exception, and it benefits from an active community of ambitious developers always working on improvements to the ecosystem as a whole. One such improvement in the works is the ERC223 token standard.

ERC20 tokens have many functions, but one thing you should never do is send them directly to a smart contract. Remember, each token is tied to a smart contract that governs its actions through code. One shortcoming of ERC20 smart contracts is that if they receive tokens directly to the contract address, they cannot send them back out again.

ERC223 seeks to fix this issue with a fallback ‘return to sender’ function, where these misplaced tokens can be refunded or returned, instead of stuck permanently in a smart contract. Since the Ethereum blockchain is immutable, this only applies to contracts that will be created after the widespread adoption of this new code. All tokens that are currently stuck in smart contracts will remain there indefinitely.

New token standards are constantly being innovated by the Ethereum community – ERC777, ERC1155, and others. If this is something that interests you, a good place to explore new Ethereum proposals is the Fellowship of Ethereum Magicians, an active discussion board for Ethereum developers. For now, ERC20 and ERC721 are the most widely used and accepted token standards for Ethereum, but as other proposals become fully implemented, MEW is committed to integrating the latest Ethereum technology with the platform.

That’s all folks!

Now you’ve been acquainted with the basic categories of tokens that exist on the Ethereum blockchain at this time. Take this information with you when searching for cryptocurrencies to invest in, because the choices can get overwhelming. New tokens are being launched daily, but it’s up to the investor to determine if their vision and goals align with the token’s purpose.

If you feel strongly about these subjects, join the discussion on Reddit or Twitter. Make yourself heard! The Ethereum community is very accepting of new ideas. While you’re at it, don’t forget to follow us on Twitter and Reddit for updates and more educational articles, like this one.

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About Stephen Wooldridge II

I'm Educational Project Lead at MEW, dedicated to bringing awareness and education about blockchain technology to the masses. The only way to move forward is by moving together.
  • Los Angeles, CA

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