Off-chain transactions that take place may later be reported or bundled together before being sent to the main chain.
Ransomware
Ransomware is a type of malware (malicious software) that has the final goal of convincing victims to pay for a decryption ransom in order to recover their compromised files or system. The payments are normally asked in digital currencies that are difficult to be traced, such as Bitcoin, Monero, or any other cryptocurrency.
Candidate Block
In a few words, a candidate block is a block that a mining node (miner) is trying to mine in order to receive the block reward. So a candidate block may be described as a temporary block that will be either validated or discarded by the network. Miners compete with each other to validate the next block and add it to the blockchain, but first, they have to create a candidate block to participate in the mining competition.
Coin
Cryptocurrencies known as coins run on separate blockchains and are unrelated to other coins. Such a cryptocurrency's single unit is also known as a coin.
