What is a split-brain in the context of Oracle RAC?

As a qualified Oracle RAC administrator, you should easily recognize terminology and acronyms specific to this profession. Once you recognize the terminology, you can begin to answer the interviewer's question. Suppose, for some reason, the terminology or the acronym is unfamiliar to you. In that case, you should readily admit this and either ask a qualifying question or explain to the interviewer how you would find the information needed to respond to their question.

"Occasionally, database nodes in an Oracle RAC cluster may be unable to communicate with each other. When this occurs, they may continue to independently process and modify the data blocks. When multiple instances modify the same block, the data blocks cannot synchronize, and other instances will do those writes for the same block. This process is called split-brain."