What is an orphaned block?

An orphaned block is a valid block that the network discards because a competing block was accepted first. When two miners find blocks at nearly the same time, the network has to choose one — the other is dropped and the mining effort behind it is lost. The source paragraph illustrates this: if Node A and Node B each find a block before they know about each other's work, the network must orphan one of them. This matters because orphaned blocks represent real electricity and hardware cost spent on work the network ultimately ignores, which also limits how fast blocks can be safely produced.