These terms are used to indicate the general trend of the graph, whether it’s going up or down. They are named after these animals because of the ways they attack their opponents. A bull thrusts its horns up into the air, while a bear swipes its paws downward. So these animals are metaphors for the movement of a market: If the trend is up, it’s a bull market. But if the trend is down, it’s a bear market.
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.
Homero Josh Garza, who founded the cryptocurrency startups GAW Miners and ZenMiner in 2014, acknowledged in a plea agreement that the companies were part of a pyramid scheme, and pleaded guilty to wire fraud in 2015. The U.S. Securities and Exchange Commission separately brought a civil enforcement action against Garza, who was eventually ordered to pay a judgment of $9.1 million plus $700,000 in interest. The SEC's complaint stated that Garza, through his companies, had fraudulently sold "investment contracts representing shares in the profits they claimed would be generated" from mining.
Double spending means, as the name suggests, that a Bitcoin user is illicitly spending the same money twice. With physical currency, this isn't an issue: Once you hand someone a greenback $20 bill to buy a bottle of vodka, you no longer have it, so there's no danger you could use that same $20 to buy lotto tickets next door. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original."
Here’s why. Ethereum is based on blockchain technology where all transactions are meant to be irreversible and unchangeable. By executing a hard fork and rewriting the rules by which the blockchain executes, Ethereum set a dangerous precedent that goes against the very essence of blockchain. If the blockchain is changed every time a large enough amount of money is involved, or enough people get negatively impacted, the blockchain will lose its main value proposition – secure, anonymous, tamper proof & unchangeable.
IE… I have 50 ETH , and want to buy a ‘widget’ for 25 ETH given a particular set of circumstances (it works, or the temperature is >10c tomorrow). I agree with a seller on the conditions of a contract, and we ‘create’ a contract on an Ethereum platform, with appropriate sign-offs and verification. This could be 2 steps, or it could be 1000 steps. Once established in the ‘smart contract’, if it is indeed >10c tomorrow, the contract automatically shifts 25 ETH to your account and ships me my widget. The results are recorded in the blockchain.
Cryptocurrency mining is a way to get Bitcoins. Of course, it is possible to buy them, but Bitcoin mining creates new ones by making new parts of the blockchain. In defining cryptocurrency mining, it should be stated how it actually works. In order to mine, there must be a peer-to-peer computers network so that tasks can be performed with their combined computing power. The more computers and less centralized the system, the faster tasks will be operated. Each computer is called a host in the blockchain and the network works based on a cryptographic protocol. By recording and confirming new operations into a virtual, replicated, and distributed public database known as the blockchain, miners (those who do mining) create new parts of the chain and they receive 12.5 Bitcoins for each new part as a reward. The new block can be made just once in 10 minutes so that to synchronize all operations, assure they are mathematically accurate and be able to spread it around all users.
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.