A block explorer is an online app that allows the to discover the details of all of the transactions that have ever transpired on a particular blockchain.
A block explorer is like a search engine for a specific blockchain that enables you to find specific data on a blockchain. This can be anything from the date and time a particular block was mined, inter-wallet transactions made by ERC-721) tokens that operate through the Ethereum blockchain, with all contracts being authenticated and stored on the it as well.
It is a type of software that operates by using both an Application Programming Interface (API) and hodlers and news sites, among others.
