A boundary across which two systems communicate. An iNTerface might be a hardware connector used to link to other devices, or it might be a conveNTion used to allow communication between two software systems. Often there is some iNTermediate componeNT between the two systems which connects their iNTerfaces together. For example, two EIA-232 iNTerfaces connected via a serial cable. See also graphical user iNTerface, {Application Program INTerface}. (1996-05-22)