# Glossary

Account

A user account is specified by an address on TOP Chain. An account is an object containing state information and logic, including things like the Balance, Properties which store data, and Actions for each property. The account balance can also be treated as a special type of property of the account object.

An action could be a system-level function such as a transfer, or a customized action governed by a smart contract deployed by the account owner. The account object and its methods can be easily and flexibly extended with new properties and customized actions.

Across-account Transaction

The sender and receiver accounts for transactions are different, such as a transfer or running contract.

Action

An action provides flexible processing capabilities for a property. An action can be a built-in system function such as Hash and Vote, or a user-defined smart contract. Users can trigger an action by sending a transaction or a message.

Beacon

TOP AI Network’s Beacon Chain acts as the coordinator and archive for the system. The Beacon Chain handles node registration and elections(archive,edge,Beacon, etc.) along with staking, voting, slashing, work-load logging and on-chain governance. These parameters and processes are logged and handled through Beacon Chain smart contracts. The Beacon Chain also acts as a global clock for the whole system through the production of timing blocks at regular intervals.

Blockchain Browser

The search engine that helps users retrieve on-chain information. TOP AI Network's block browser is "topscan.io".

Consensus Mechanism

To achieve data consistency in the decentralized system, a node must be selected through some mechanism to decide which transaction should be processed at this time, and the execution result of this transaction should be broadcast to other nodes for verification or storage, so as to achieve the consistency of node data in the whole network. This node is called the "leader", and the mechanism by which the leader is selected and the data are agreed is called the "consensus mechanism".

TOP AI Network consensus mechanism: hpPBFT-PoS*.

Keystore File

keystore file is a private key encrypted file that is user-specific and used to sign transactions, allowing keys to be stored in an encrypted manner.

Message

A message is an instruction that initiates an action on a property of an account. Data attached to a message contains the property, action, input parameters and output parameters. For security purposes, a message cannot alter the account balance.

Node

Every server in a blockchain network is a node. TOP AI Network has five types of nodes: edge, validator, advance, archive and exchange. In which the advance node has the roles of validator, auditor.

Property

A property of an account is a user-defined data object, which is added as a key-value pair. The key is an arbitrary String whose value can be any data type, such as an Integer, String, List, HashMap, etc.

The account balance, a special property, exists by default when the account is generated.

Public-private Key

A public key is an expression of an account, while a private key is the password of the account. Public and private keys always exist in pairs and are generated by asymmetric encryption algorithm. The private key is private and only owned by the account owner and is used for encryption; The public key is public and used for decryption.

Receive Transaction

For the receiver account, the transaction is called the receive transaction.

Send Transaction

For the sender account, the transaction is called the send transaction.

Shard

Sharding is one of the main schemes of system linear expansion. TOP AI Network adopts multi-sharding technology to realize linear expansion, including all sharding of Network, computing and state.

Single-account Transaction

The sender account and the receiver account are the same, and the account operates on its own properties.

Smart Contract

A smart contract is automated, binding agreement between two or more parties. Every single line of code in the contract gets executed sequentially and the output result of the contract gets immutably added to the blockchain.

TOP AI Network smart contract includes the platform smart contract and application smart contract.

Staking

Staking is the process of locking up TOP tokens to exchange rights (gas, votes ,etc.) on blockchain.

Transaction

A transaction refers to an instruction that initiates an asset transfer from one account to another. A transaction can also contain an action that will be triggered when the transaction is being processed.

Transaction Receipt

The transaction receipt consists of the transaction multiple signatures and the Merkle tree path. The function of the transaction receipt is to prove that the transaction consensus is successful, including sending transaction receipt and receiving transaction receipt.

Wallet

The TOP AI Network wallet application is "HiWallet". HiWallet is a secure decentralized blockchain digital wallet with multiple layers of encryption. It supports TOP, BTC, ETH, BCH, DASH, LTC, etc.

Wallet Address

Wallet address is the account address on the blockchain, consists of a String of characters and numbers. A TOP AI Network wallet address looks something like this: T800002276a7d58218ac4978733e5cca927a7d86cb7c87.