* The difference between a language and a dialect is subjective: There's no definitive scientific definition. Linguists often use the "mutual intelligibility" criterion: if speakers can understand each other, it's a dialect; if not, it's a separate language. However, this is messy, as many languages have dialects that are not mutually intelligible.
* Political and social factors play a role: Sometimes, a language is considered a dialect for political reasons, like to downplay the importance of a minority language.
* The number of dialects is constantly evolving: Languages change over time, and new dialects can emerge.
Instead of asking how many languages are dialects, it's more accurate to say:
* There are countless dialects of many languages around the world.
* The number of languages is also constantly debated, but there are likely thousands.
If you're interested in learning more about specific languages and their dialects, I recommend researching them individually.