Historically, banks have controlled both the hardware (chequebooks and debit/credit cards) and the distribution (branches, websites, etc).
历史上，银行业既掌握着硬件（支票簿和贷/借记卡），有控制着流通机构（分支企业，网站等等）。
2
The trial is only a working paper of the accountant, not intended for distribution to others, but it's a strong tool to see whether the debit and credit balance of all the accounts are equal.