Hello everyone, hope you are all doing great. I welcome you all to my fifth homework task provided by @besticofinder. Thanks to @steemitblog for this awesome initiative.

First of all, we can classify all cryptocurrencies into two types. One is minimal, the other is pre-generated. Bitcoin is the first-ever cryptocurrency that was created in 2009 by an anonymous person named Satoshi Nakamoto. Some other coins like Ethereum, Light-coin, Zcash, Monero, etc. can also be mined. Coins that cannot be mined include Ripple, Iota, etc. Mining can be done with a PC at one time but now it is not possible. Bitcoin mining is not even convenient with a rig of 8 ~ 16 GPU. Bitcoin mining is nowadays done with ASIC miners specially designed to work with the SHA-256 hashing algorithm. However, getting this hardware is not so easy. Production is very low and they are pre-sold before they hit the market. Again the price is quite high. Anyone can mine with a GPU rig if he/she wants, again, there are many coins whose algorithm is designed in such a way that they cannot be mined with an ASIC miner. Another way for bitcoin mining is cloud mining. Some companies have set up mining firms in low-cost areas with low-cost electricity facilities. They sell hash power and pay for that proportion of bitcoins excluding electricity and maintenance costs. But there are many organizations that are doing fraud to the customers. Based on my long track record and reviews, I'm pretty sure the three companies are legit.

Genesis Mining: I think genesis mining is the most transparent cloud mining provider in this industry. Because of its transparency, It has a huge demand on the market. All the contracts are already sold over. The most surprising fact is the members who bought contracts last November will start mining this month.

Hashflare: Hashflare is another very efficient cloud mining tool. It's very easy to use, not so expensive, and time-saving. Customers can buy hashrates easily. First, it is important to note that the SHA-256 mining contract is the most profitable. However, the recent rise in the price of ethereum has become quite profitable ETHASH. All contracts are not sold yet. Few more are also remaining. Again, There are many calculators to calculate the profitability of mining.

CCG Mining: CCG Mining has not been on the market for a long time but its activities are quite transparent. Videos of their mining setups, rigs, etc. are available on YouTube, as well as on CCG's website, which is actually a great way to gain confidence. Social media, LinkedIn profiles, etc. with pictures of CCG Mining's team members can be seen by anyone and they are all real people, not fake IDs. Considering all these aspects, CCG Mining seems to be quite good and ‘legitimate’. The best thing is that their bitcoin mining contract is open-ended, meaning lifetime. This contract will continue as long as the cost of daily maintenance at least rises from the mining income.

Advantages of Cloud Mining:

• No installation and maintenance charge.
• No noise or heat generation.
• Easily Accessible.

Disadvantages of Cloud Mining:

• Tend to commit fraud.
• Diminishing returns.
• No control and suppleness.
• Vulnerable and transparent.