UI is the point when interactions between machines and people happen. It lays down the parameters of a user's interaction with a machine.
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.
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.
Governance Token
Developers design governance tokens to let token holders influence the direction of a protocol.