Public Key – Are there 2^160 possible addresses or are there 4*2^160 (4 address types) possible addresses?

In fact, there are currently five commonly used address types (P2PKH, P2SH, P2WPKH, P2WSH, P2TR), two of which encode 32-byte (256-bit) values ​​rather than 20-byte (160-bit) values. ) Since there is 1, the actual number of possible addresses is 2*2^256 + 3*2^160.

Technically, you can convert between some address types. For example, P2PKH and P2WPKH both encode the same type of public key hash. But you should never do this. This is because 1) the recipient will almost certainly not monitor the blockchain paying to the converted address, and 2) they may not be able to use the coins sent to the converted address. The key is in a hardware security module that only works with the original address type. Always send to the exact address provided.