The first decentralized cryptocurrency, bitcoin, was created in 2009 by pseudonymous developer Satoshi Nakamoto. It used SHA-256, a cryptographic hash function, as its proof-of-work scheme. In April 2011, Namecoin was created as an attempt at forming a decentralized DNS, which would make internet censorship very difficult. Soon after, in October 2011, Litecoin was released. It was the first successful cryptocurrency to use scrypt as its hash function instead of SHA-256. Another notable cryptocurrency, Peercoin was the first to use a proof-of-work/proof-of-stake hybrid.
The above list shows that, fundamentally, yes, anyone can mine cryptocurrencies; however, you must have a keen interest in mining, as well as an appetite to constantly learn and keep up to date on any technology changes. You also have to have the initial budget to be able to set up everything that is required. So, although, technically anyone can mine, realistically, it is not suited to everyone.
As of May 2018, over 1,800 cryptocurrency specifications existed. Within a cryptocurrency system, the safety, integrity and balance of ledgers is maintained by a community of mutually distrustful parties referred to as miners: who use their computers to help validate and timestamp transactions, adding them to the ledger in accordance with a particular timestamping scheme.
First, here is an example of how a standard forex trade works. Imagine you are an American trader betting on the British pound/U.S. dollar currency pair (GBP/USD). You deposit $100 with your forex broker. Assuming the rate of $1 = £0.5, you will receive £50 for your $100. If the GBP/USD rate changes to 0.45, you close the position to 50/0.45 = $111.11. That is, you make a 11.11% profit over your initial $100 deposit.
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."
Bitcoins are mined with powerful computer hardware and software. A maximum of 21 million Bitcoin will be available, after which no further bitcoins will be produced. The algorithm which governs the production of Bitcoin limits the quantity that will be produced, and the rate at which they will be produced. It is a finite commodity – there is a fixed amount, and that ensures that greater demand will always prop up the price. In this way, it is similar to other finite commodities such as crude oil, silver, or gold.