A blockchain is a public ledger of information collected through a network that sits on top of the internet. The way this information is recorded is what makes Blockchin so specisl and outstanding. 

Documentation of data on the internet is what Blockchain is and no it is some sort of company, nor is it an app. Blockchain applications can be made use of for creating social networks, messengers, games, exchanges, storage platforms, voting systems, prediction markets, online shops and much more.

“The Internet 3.0” is what it is called, and in some way it does share certain similarities with the internet.

Money transfer, ownership, an identity, an agreement between two parties, you name it and the information recorded on Blockchain would take that form.

A confirmation from devices like a computer or other devices on the network is needed and once an agreement is done between the devices, something stored on Blockchain by them stays there. Unless their permission granted by the owners of the record, It cannot be disputed, removed or altered.