The differences between finger-style and classical guitar technique are not confined to a technical level only
For starters, the tool is really different.
While the classical guitar and the metal-string guitar may look quite similar, not only are the shape and construction technique not the same, but the strings and bridge are also completely different.
Classical guitars have wide, thick necks with nylon strings, while acoustic guitars have thinner, narrower necks and metal strings.>
The two techniques instead share the use of the fingers to pluck the strings but, while the classical technique, deriving from centuries of tradition, is extremely precise and accurate, the fingerstyle technique is much more recent and less rigid.