1.) Distributed Ledger Technology (DLT) is a special form of electronic data processing and storage. A Distributed Ledger or „Distributed Accounts Book“ is a decentralized database that allows users of a network to share read and write permissions. Unlike a centrally managed database, this network does not require a central instance that makes new entries in the database. New records can be added at any time by the participants themselves. A subsequent update process ensures that all participants have the latest version of the database. A special feature of the DLT is the blockchain.
2.) Configurations: Dependent on the access possibilities of the participants in a network Distributed Ledgers can be subdivided into „permissioned“ and „unpermissioned“ Ledgers. While the latter are openly accessible to anyone (such as the Blockchain in Bitcoin network), access to the account book is regulated at the former. Participants in networks with permissioned ledgers are generally registered and meet certain requirements for access to the account book. The choice of the circle of authorized users (open or limited circle of participants) also involves the choice of the consensus mechanism. For example, proof-of-work mechanisms are primarily used for unpermitted ledgers, since the validation of entries requires no trust among the participants. On the other hand, permissioned ledgers use proof-of-stake or PBFT consensus mechanisms that require less computing power. The establishment of a basis of trust in this case already takes place through the admission of the participants to the network.