There is indeed cryptocurreny and Bitcoin is one type of cryptocurrency.  If you are talking about altcoins then I can say that not all altcoins are safe and secure.  Bitcoin is proven to be a secure cryptocurrency and it is very safe due to the massive hash that is securing it.  While other cryptocurrency known as altcoins pretend to be secured but are often susceptible to hacking especially their smartcontract and Defi.  Most of these altcoins are centralized because they can be controlled and even freeze anyone's transactions and can even blacklist any address if they wanted to.


When it comes to market both Bitcoin and altcoins are highly volatile, the difference is that Bitcoin is highly liquid because of the trust it caters from the community and the demand of people in wanting to have a grasp of Bitcoin.  While there are some altcoins that have a good liquidity, most of them does not have and may become worthless overnight.


I somehow disagree, there is no doubt that Bitcoin is the real deal but there are few altcoins that bring innovations to the table.

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There is no doubt that Bitcoin Network security is the best due to its POW system and the massive hashes that securing its network.  Ever since its last exploit[1], which is announced in this thread[2], the adjustment made on Bitcoin system proves that it is the safest and secure network in cryptocurrency because no hack had been successful after that incident.

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[1] https://decrypt.co/39750/184-billion-bitcoin-anonymous-creator
[2] https://bitcointalk.org/index.php?topic=822.0