(a) Yes. (b) No.
An accrual tax system is what most of us are familiar with. Each pay cheque or taxable receipt we get accrues towards a total tax bill. Then at year end we recalculate and revise the tax amount due and either remit the unpaid difference or receive a tax refund.
A remittance-based system looks at each transaction as a stand alone transaction. some transactions might be treated similarly as a group but each is still its own transaction. Once the tax is determined on that transaction it is due and payable. No annual reconciliation occurs.
How is this different?
In an annual accrual system a bonus might be paid when it is estimated that you are in a low tax bracket and then by the end of the year you are in a high tax bracket. The bonus is recalculated and more tax is requested. In a remittance system the bonus and its tax is not adjusted.
Canada is an example of an accrual system. China is an example of a remittance system.