Private blockchain allows the selection of partners and participants forming the blockchain network, thanks to which industry networks are built. The private blockchain ensures security and confidentiality of information, and the data writing itself is fast and does not require as large resources (related to e.g. power consumption) as public networks.
It is not worth dwelling on what blockchain technology itself is today.
Blockchain Compass 2018 is a report explaining the idea of blockchain and many related issues. Experiences from specific implementations are shared by the representatives of Microsoft and Atende