Edom and Idumea are two related but distinct terms relating to a historically contiguous population, but two separate, if adjacent, territories occupied at different periods of their history by the Edomites/Idumeans. The Edomites first established a biblical kingdom ("Edom") in the southern area of modern Jordan, and later migrated into southern parts of the Kingdom of Judah ("Idumea") when Judah was first weakened, then destroyed by the Babylonians in the 6th century BC.

errno.h is a header file in the standard library of the C programming language. It defines macros for reporting and retrieving error conditions through error codes stored in a static memory location called errno (short for "error number").