Main Page | See live article | Alphabetical index In telecommunication, the term on-line has the following meanings: 1. Pertaining to the operation of a functional unit when under the direct control of the system with which it is associated. Note 1: On-line units are available for immediate use on demand by the system without human intervention. Note 2: On-line units may not be independently operated. 2. Pertaining to equipment that is connected to a system, and is in operation. Source: from Federal Standard 1037C and from MIL-STD-188 This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.