IEC TR 61788:2014 which is a technical report, provides general characteristics and guidance on practical superconducting (SC) wires. Particular focus is given to the characteristics that are different from those of ordinary copper and aluminium wires, since practical SC wires have appearance nearly identical to common electrical wires and can be used interchangeably with them. On the other hand, the practical SC wires are typically composite materials consisting of several functional materials. Many forms of SC wires are described in Section 4 of IEC 60050-815, including single core wires, multi-filamentary superconducting wires, composite superconductors and coated conductors. These wires as well as others that might be described as monolithic composite superconducting wires will be the focus in this technical report. A wire is considered as being practical if it can be procured in sufficiently continuous lengths under ordinary commercial transactions to build devices. Conductors made of multiple wires, such as cables, for example, are not included in this scope. Since this report only addresses the characteristics of practical wires, other wires such as prototype, test sample and developmental wires are not included in the scope of this technical report. Key words: superconductivity, supraconductivité