Definition(s)
Connection
Assembly consisting of either two pins and a coupling or one pin and an integral box.
Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global Standards
Connection
Threaded assembly of tubular components.
Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global Standards