Exactly. Many database systems operate as a cluster where one server acts as master, and the rest are slaves that replicate the master
And to answer the question in OP, “whitelist” means “nothing is allowed unless it’s on the list,” and “blacklist” means “everything is allowed unless it’s on the list.” Both are useful in various contexts
It’s used in the IT world, typically with network security. Essentially the opposite of a blacklist.
Guessing that’s where the master/slave thing come in too?
Exactly. Many database systems operate as a cluster where one server acts as master, and the rest are slaves that replicate the master
And to answer the question in OP, “whitelist” means “nothing is allowed unless it’s on the list,” and “blacklist” means “everything is allowed unless it’s on the list.” Both are useful in various contexts