This pattern is named bulkhead because it behaves as the partition of a ship to prevent the ship from sinking. It basically isolates the various compartments of a ship to avoid or minimize the risk of sinking.
The same applies to software, where one failure does not compromise the entire system. In IT, specifically when implementing a data access layer, the bulkhead pattern should be used for connection pools. Either a database, or HTTP connections that have one single connection pool, could compromise the entire system. Suppose your code does not release connections properly—the connection pool would be full of active connections very quickly, and in that case, services dealing with databases or other services via HTTP connections will not be able to function properly, even if they have to deal with different resources.
The following image depicts various applications...
