Now that there is a lot of Altcoin in the market, do you know how many types it has?
I would share the altcoins by the consensus mechanisms that they use. There are already a great number of consensus algorithms, I will not disclose their theoretical part, I'll give just examples.
1. Proof Of Work / PoW (Bitcoin, Ethereum, Litecoin, Monero, ZCash, Dogecoin, etc).
2. Proof of Stake / PoS (VCash, BitBay, Peercoin, Qtum, Stratis, etc).
3. Proof of Stake Time / PoST (Vericoin).
4. Delegated Proof Of Stake / DPOS (Steemit, EOS, BitShares).
5. TAPOS.
6. dBFT (NEO).
7. BFT (Hyperledger, Stellar, Dispatch, and Ripple).
8. Proof Of Activity (Ethereum Kovan).
9. Proof Of Burn (Slimcoin).
10. Proof of Weight (Algorand, Filecoin, Chia).
11. Proof of Capacity.
12. Proof of Storage (SC).
13. Proof of Checkpoint / PoC.
14. Proof of Importance (NEM).
15. Directed Acyclic Graphs (Iota, Hashgraph, Raiblocks/Nano).