Electronic settlement is an online exchange of funds between buyers and sellers. The contents of the exchange are usually digital financial instruments issued by banks or intermediaries and supported by legal tender. There is a credit card settlement; Electronic cash settlement; Electronic check settlement; Electronic wallet settlement; Debit card settlement; Electronic token settlement, etc.

A section of wire, whose two ends are called end A and end B respectively ... The image point should be that when an electron enters from end A, the electron in the wire will take a step towards end B (the effect of electric field), so that the electron closest to end B in the original wire will come out. But in fact, the situation is more complicated, because the electrons are constantly moving around the nucleus, and the free electrons in the conductor are also constantly moving, but there will be a distribution balance (diffusion principle) in a certain sense. We can think abstractly that the free electrons in the conductor are regular.