Short Answer:
Taylor Guitars V-Class bracing is a V-shaped acoustic guitar bracing pattern that exists as an alternative to traditional X-shaped bracing. The design, engineered by Taylor Guitars Master Builder Andy Powers, rearranges areas of top wood rigidity and flexibility to enhance tonal balance and projection.
Long Answer:
So, there's a little bit of acoustic guitar science and philosophy at work, here. At the center of Taylor Guitars' V-Class bracing patterns is an inherent conversation between sustain and volume. Sustain and volume, the two basic pillars of acoustic instrument design, balances the two physical qualities of rigidity and flexibility. Think of a string resonating against a rigid wood like a Les Paul body. The Les Paul's rigidity will cause the string to vibrate for a longer period of time, but won't make much sound. Now think of a banjo. Its drum-like head membrane is incredibly flexible, so strings vibrating against it will produce a louder sound, but have much less sustain. This inherent conflict between top wood sustain and top wood projection has driven acoustic guitar bracing design for generations.
Today's V-Class bracing rewrites the story on the conflict between sustain and volume. Traditionally, an X-shaped bracing pattern was the standard for acoustic guitars. It still typically is, but Taylor's newer V-Class bracing pattern still seeks to make improvements where improvements can be made. What this is all based around is making some areas of a V-Class braced top wood rigid and some areas flexible, essentially redirecting the travel of vibrations. V-Class bracing aims to normalize the randomness of top wood vibrations, historically made random with X-shaped bracing patterns, by trying to strike a balance between flexibility and rigidity.
The science behind V-Class bracing is about directing vibrations to a more focused tonal sum. In a world of randomness, it can be nice to know that your acoustic guitar bracing pattern has it all figured out.