It is said of what travels, connects or communicates from the point of origin to the point of destination without relays or intermediate nodes. The expression is not always taken as literal, since in many cases it is impossible to connect without going through other points in between, but if they are considered as transparent and do not interfere with the content or the moving object it can be used the same. It is sometimes confused with "point by point" ("item by item", "case by case") , perhaps by the expression "one by one", but it is a mistake and should be avoided. See from end to end.
