Some classical guitarists (understandably, if they haven't studied flamenco) view flamenco as a "style" of guitar playing emphasizing certain techniques above others and having a distinct sound. Thus (oversimplified) if you play rhythmic rasqueados and fool around with Phyrygian scales and a lot of Ami>G>F>E, it's flamenco. Not so. At most, flamenco-ish.

Flamencos themselves (i.e., guitarists, dancers, singers, aficionados), whatever their own specialty, and for both formal and historical reasons, usually agree that what is fundamental to flamenco is cante (song), i.e., a body of several dozen forms with specific rhythms, melodies, and in some cases themes, sung in a certain way.

Flamenco guitar started as accompaniment for cante, and in Spain has largely remained that, no matter how technically refined it has become. Probably the same is true of flamenco dance -- that it started as an embellishment through movement of what the singer was doing. Even the virtuosos like Paco de Lucia and the late Sabicas who are famous for solo work (and who play other music besides flamenco) would probably define flamenco in terms of cante rather than of guitar technique. Both started within the tradition as accompanists of cante, and were superb ones. To anyone familiar with cante, even their solos imply the cante from which they came.

[This is an excerpt from The Flamenco FAQ for Classical Guitarists, which was written expressly for publication on Guitarist.com many years ago by Bob Clifton. The FAQ has since "migrated" all over the Internet, but Guitarist.com is its true home.]