BIP44 generation tool has Account xpubkey & bip32 xpubkey, what's the difference? recently i played with the tool generation of HD address on https://iancoleman.github.io/bip39/. after input mnemonic code and check the derivation path, why is there Account Extended Public Key &amp; BIP32 Extended Public Key? What's the difference between 2? Can i use Account xpubkey to generate the same address as bip32 xpubkey? 

please advice,
BIP 44 just specifies a structure for organising keys using BIP 32 style generation. The tree structure is this:

 m / purpose' / coin_type' / account' / change / address_index


Generally, m refers to your BIP 32 master private key generated from the mnemonic in BIP 39. But all children extended keys are also extended parents if you want them to be - all can have children. So Account extended public key will just be the extended public key generated as a child of the coin_type extended key from the hierarchy above.