44' (or 0x8000002C) following the BIP43 recommendation. It indicates that the subtree of this node is used according to this specification. Hardened derivation is used at this level.0. This number is used as the child index in BIP32 derivation. Hardened derivation is used at this level.index - 1) has no transaction history (i.e., none of its addresses have been used).0 and 1 are used for the external and internal chains, respectively. The external chain is used for addresses that are meant to be visible outside of the wallet context (i.e., for receiving payments). The internal chain is used for addresses which should remain private within the wallet context; this chain is used to store change returned from broadcast transactions. Public derivation is used at this level.0 in sequentially increasing manner. This number is used as child index in BIP32 derivation. Public derivation is used at this level.