Cryptocurrencies is the name of all these coins(Bitcoin, Etherum, nano coin and Tron)
It's just a General name given to those coins.
While Bitcoin is the actual coin been bought and traded
Cryptocurrencies Is a father or the name of all the coins. If you say bitcoin you are referring to cyptocurrencies, when you say cyptocurrencies you are also referring to bitcoin or Etherum many other. There is no difference in the two
Cryptocurrency is the trademark name for all coins like Bitcoin, Litecoin, Bitcoin cash, Ethereum etc. They're all called Cryptocurrency, cos they're digital assets in virtual pattern.