2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/65561This article, addressed to a general audience of functional analysts, is intended to be an illustration of a few basic principles from `noncommutative functional analysis', more specifically the new field of {\em operator spaces.} In our illustration we show how the classical characterization of (possibly non-surjective) isometries between function algebras generalizes to operator algebras. We give some variants of this characterization, and a new proof which has some advantages.12 pages - Intended for Conference ProceedingsFunctional AnalysisOperator AlgebrasPrimary 46L07, 46L05, 47L30; Secondary 46J10text