As with other cryptocurrencies, the validity of each ether is provided by a blockchain, which is a continuously growing list of records, called blocks, which are linked and secured using cryptography. By design, the blockchain is inherently resistant to modification of the data. It is an open, distributed ledger that records transactions between two parties efficiently and in a verifiable and permanent way. Unlike Bitcoin, Ethereum operates using accounts and balances in a manner called state transitions. This does not rely upon unspent transaction outputs (UTXOs). State denotes the current balances of all accounts and extra data. State is not stored on the blockchain, it is stored in a separate Merkle Patricia tree. A cryptocurrency wallet stores the public and private "keys" or "addresses" which can be used to receive or spend Ether. These can be generated through BIP 39 style mnemonics for a BIP 32 "HD Wallet". In Ethereum, this is unnecessary as it does not operate in a UTXO scheme. With the private key, it is possible to write in the blockchain, effectively making an ether transaction. To send ether to an account, you need the public key of that account. Ether accounts are pseudonymous in that they are not linked to individual persons, but rather to one or more specific addresses. Owners can store these addresses in software, on paper and possibly in memory ("brain wallet").
More important, Nakamoto built the system to make the blocks themselves more difficult to mine as more computer power flows into the network. That is, as more miners join, or as existing miners buy more servers, or as the servers themselves get faster, the bitcoin network automatically adjusts the solution criteria so that finding those passwords requires proportionately more random guesses, and thus more computing power. These adjustments occur every 10 to 14 days, and are programmed to ensure that bitcoin blocks are mined no faster than one roughly every 10 minutes. The presumed rationale is that by forcing miners to commit more computing power, Nakamoto was making miners more invested in the long-term survival of the network.
If the Ethereum Platform is rapidly adopted, the demand for ETH could rise dramatically and at a pace that exceeds the rate with which ETH miners can create new ETH tokens. Under such a scenario, the entire Ethereum Platform could become destabilized, due to the increased cost of running distributed applications. In turn, this could dampen interest in the Ethereum Platform and ETH. Instability in the demand of for ETH may lead to a negative change of the economical parameters of an Ethereum based business which could result in the business being unable to continue to operate economically or to cease operation.
Ethereum would never be possible without bitcoin—both the technology and the currency—and we see ourselves not as a competing currency but as complementary within the digital ecosystem. Ether is to be treated as "crypto-fuel", a token whose purpose is to pay for computation, and is not intended to be used as or considered a currency, asset, share or anything else.
Use a pegged derivative: Ethereum is a great tool for creating complex trading between multiple parties. If you have a source for the price of Bitcoin that all parties trust, then it's possible to create an ethereum based currency whose value is pegged to the market value of Bitcoin. This means that you could trade bitcoins to a token that is guaranteed to always trade back to the same amount of bitcoins while still being fully compatible with other ethereum contracts.
The Ethereum Platform rests on open-source software, and there is a risk that the Ethereum Stiftung or the Ethereum Team, or other third parties not directly affiliated with the Stiftung Ethereum, may introduce weaknesses or bugs into the core infrastructural elements of the Ethereum Platform causing the system to lose ETH stored in one or more User accounts or other accounts or lose sums of other valued tokens issued on the Ethereum Platform.