Altcoin is the alternative coin and it also called as cryptocurrency (other than Bitcoin). All most popular altcoin or cryptocurrency used the same fundamentals of building blocks asn Bitcoin does. Different companies use the same technology which Btcoin use in some ways to achieve different goals.
Cardano (ADA), the fourth-largest cryptocurrency by market cap is riding high post smart contract integration date announcement by Charles Hoskinson. Cardano network has been going through a series of updates, out of which Alonzo is believed to be the most critical one. It will introduce smart contract functionality on the platfrom. The Alonzo Purple testenet