What Is the Difference between a P2PKH and a P2SH Address?

P2PKH (Pay-to-Public-Key-Hash) is the original, standard Bitcoin address format, starting with '1'. It locks funds to a single public key hash, requiring a single signature for spending.

P2SH (Pay-to-Script-Hash) addresses start with '3' and lock funds to the hash of a script. This allows for more complex spending conditions, such as multisignature requirements, without the sender needing to know the complex script itself.