Decentralized Applications (Dapps) are digital applications that are operated from a Peer-To-Peer network of devices, as opposed to using a single computer. Dapps have existed nearly as long as Peer-To-Peer networks have. They are programmed software that was specifically designed to be on the internet, whilst not be controlled by a single, central power.
Dapps do not actually have to be operated from a blockchain network. For example, BitTorrent is a Dapp that is hosted on a Peer-to-Peer network but not on a blockchain. A blockchain is essentially a specific type of Peer-To-Peer network but Dapps can exist on both.
Also, in contrast to more simplistic smart contracts such as bitcoin that facilitates transfers between two points, Dapps like BitTorrent have a limitless number of people that can participate, coming from every side of the market, some would be downloading some of the content, some people would be contributing content to the network and other individuals would be doing both at the same time.
With regards to cryptocurrencies, these Dapps do still exist and they will run from a decentralized blockchain network, which would be open source for all of the users. They will also be free from tampering or influence by any sole authority.
An example to consider would be that a Dapp could be created on a blockchain, that is very similar to a Facebook news feed, where you could post updates. However, as soon as an update is posted on this platform, nobody, not even the person who posted the update would be able to remove it. It could be possible for the person who posted the update to edit it, however, the post in its original form would be forever accessible.
Blockchain Dapps are required to fit in with certain criteria to be considered as such. These criteria can be found below.
-The Dapp must be completely open source and operate with complete autonomy, the consensus from the users should always be the motivation behind decisions.
-The Dapp’s data and transaction records must be encrypted and stored in a decentralized blockchain network to avoid weaknesses.
-The Dapp must utilize a cryptocurrency token of some description.
-The Dapp must generate cryptocurrency tokens.