A 51% attack is a potential attack on a blockchain network, where a single entity or organization is able to control the majority of the hash rate, potentially causing a network disruption.
Free public WiFi is now available in many places. Airports, hotels, and coffee shops all promote free internet connection as an added benefit of using their services. For many people, being able to connect to a free internet on the go seems ideal. This would be particularly useful for the traveling business person, now able to access their work emails or share documents online. However, there are more risks to using public WiFi hotspots than many internet users might have realized, and most of those risks are related to Man in the Middle attacks.
The Delegated Proof of Stake (DPoS) consensus algorithm is considered by many as a more efficient and democratic version of the preceding PoS mechanism.
The Lightning Network (LN) as a concept was created by Joseph Poon and Thaddeus Dryja in 2015. The main idea behind the project is to design a payment protocol that can be used as an off-chain solution for the scalability problem faced by the Bitcoin blockchain, but the concept may be applied to other Cryptocurrencies as well.
Bitcoin is the first cryptocurrency ever created. It is, basically, a digital form of money that is highly resistant to frauds and cannot be copied or destroyed. Computer and network technologies have advanced to its current state through one universal property of digital information: most of it can be easily copied.