1) Irreversible: After confirmation, a transaction can‘t be reversed. By nobody. And nobody means nobody. Not you, not your bank, not the president of the United States, not Satoshi, not your miner. Nobody. If you send money, you send it. Period. No one can help you, if you sent your funds to a scammer or if a hacker stole them from your computer. There is no safety net.


If you do have this much money tied up in Bitcoin, though, you may want a more secure space to store it. If this is the case, Coinbase offers a Coinbase vault, which has time-delayed withdrawals (giving you 48 hours to cancel a withdrawal) and the option of multiple approvers, increasing security by ensuring that all withdrawals are approved by multiple people. They also offer a multisig vault, which is basically an even more involved and more secure vault, requiring multiple keys to unlock. 


A cryptocurrency (or crypto currency) is a digital asset designed to work as a medium of exchange that uses strong cryptography to secure financial transactions, control the creation of additional units, and verify the transfer of assets.[1][2][3] Cryptocurrencies use decentralized control as opposed to centralized digital currency and central banking systems.[4]


Cryptocurrencies' blockchains are secure, but other aspects of a cryptocurrency ecosystem are not immune to the threat of hacking. In Bitcoin's 10-year history, several online exchanges have been the subject of hacking and theft, sometimes with millions of dollars worth of 'coins' stolen. Still, many observers look at cryptocurrencies as hope that a currency can exist that preserves value, facilitates exchange, is more transportable than hard metals, and is outside the influence of central banks and governments.
Then, in early 2009, an anonymous programmer or a group of programmers under an alias Satoshi Nakamoto introduced Bitcoin. Satoshi described it as a ‘peer-to-peer electronic cash system.’ It is completely decentralized, meaning there are no servers involved and no central controlling authority. The concept closely resembles peer-to-peer networks for file sharing.
Transaction fees for cryptocurrency depend mainly on the supply of network capacity at the time, versus the demand from the currency holder for a faster transaction. The currency holder can choose a specific transaction fee, while network entities process transactions in order of highest offered fee to lowest. Cryptocurrency exchanges can simplify the process for currency holders by offering priority alternatives and thereby determine which fee will likely cause the transaction to be processed in the requested time.

Litecoin was one of the first cryptocurrencies after Bitcoin and tagged as the silver to the digital gold bitcoin. Faster than bitcoin, with a larger amount of token and a new mining algorithm, Litecoin was a real innovation, perfectly tailored to be the smaller brother of bitcoin. “It facilitated the emerge of several other cryptocurrencies which used its codebase but made it, even more, lighter“. Examples are Dogecoin or Feathercoin.


This flexibility makes Ethereum the perfect instrument for blockchain -application. But it comes at a cost. After the Hack of the DAO – an Ethereum based smart contract – the developers decided to do a hard fork without consensus, which resulted in the emerge of Ethereum Classic. Besides this, there are several clones of Ethereum, and Ethereum itself is a host of several Tokens like DigixDAO and Augur. This makes Ethereum more a family of cryptocurrencies than a single currency.
If you want to trade in digital currencies, you are going to need a platform on which to trade them, and an intermediary to communicate with the network. Coinbase is a global digital asset exchange company (GDAX), providing a venue to buy and sell digital currencies, as well as send information about those transactions out to the blockchain network to verify those transactions. Coinbase serves as a wallet, too, where the digital currencies can be stored. The application operates exchanges of Bitcoin, Ethereum, Bitcoin Cash, and Litecoin, as well as other digital assets with fiat currencies in 32 countries, and Bitcoin transactions in many more countries. According to its website, Coinbase has served over 10 million customers and facilitated the exchange of more than $50 billion worth of digital currency.


I have not been using Coinbase long but I have used it long enough to feel like I’m getting burned. I am using Coinbase as, what I call, a pass through as in the end, I am purchasing crypto that is not supported by Coinbase with the BTC I purchase through Coinbase. While the app itself is great as it is easy to navigate the process of withdrawing funds is not so great. I purchased BTC with the intent of withdrawing to purchase another crypto. A week and several emails later my BTC has not yet been released for withdraw. Prior to this transaction I had done several others successfully with no issues, now, for no reason whatsoever my funds are pended for “further research”. I am a patient person but as I’m sitting here waiting the BTC value is falling and the cost of the crypto I am looking to purchase is rising which means at this point I have missed out on a few hundred dollars of profit all because Coinbase won’t release my funds. I am giving only 1 star because (1) communication with Customer Service has not been great as I am still sitting here clueless on what’s going on and (2) I’ve missed out on significant profit and have no idea why or have any sense of comfort that this won’t be an ongoing issue
Despite the intricate technology associated with and necessary for cryptocurrency investing, speculation and possession, Coinbase has created an apparatus that makes this process remarkably easy and familiar, almost like buying and selling stocks. This screenshot from the Coinbase site shows real-time cryptocurrency prices and doesn't look too different from your ordinary online stock tracker.


Darknet markets present challenges in regard to legality. Bitcoins and other forms of cryptocurrency used in dark markets are not clearly or legally classified in almost all parts of the world. In the U.S., bitcoins are labelled as "virtual assets". This type of ambiguous classification puts pressure on law enforcement agencies around the world to adapt to the shifting drug trade of dark markets.[75]


When it comes to other, less popular cryptocurrencies, the buying options aren’t as diverse. However, there are still numerous exchanges where you can acquire various crypto-coins for flat currencies or Bitcoins. Face-to-face trading is also a popular way of acquiring coins. Buying options depend on particular cryptocurrencies, their popularity as well as your location.
As a cryptocurrency attracts more interest, mining becomes harder and the amount of coins received as a reward decreases. For example, when Bitcoin was first created, the reward for successful mining was 50 BTC. Now, the reward stands at 12.5 Bitcoins. This happened because the Bitcoin network is designed so that there can only be a total of 21 mln coins in circulation.
Once you bought your cryptocurrency, you need a way to store it. All major exchanges offer wallet services. But, while it might seem convenient, it’s best if you store your assets in an offline wallet on your hard drive, or even invest in a hardware wallet. This is the most secure way of storing your coins and it gives you full control over your assets.