What is the difference between cryptocurrencies and tokens?

Could you elaborate on the key distinctions between cryptocurrencies and tokens? I'm particularly interested in understanding the fundamental differences in terms of their purpose, functionality, and regulation. Do cryptocurrencies, such as Bitcoin, operate independently as a form of digital currency, while tokens, like those found on Ethereum, serve as representations of assets or utility on a blockchain? Also, how do regulatory frameworks differ for these two digital assets, and what implications do these differences have for investors and users?