Maybe it has meaning in a high school text book where they are trying to teach basic concepts of digital communications.
The 1's and 0's in USB are not +5v and 0v. There are no pulses. The difference in the D+ and D- voltages indicate the data. This is differential signalling. With single ended signalling - such as TTL, data is indicated by the presence or absence of voltage. I think you are confusing the two.
Maybe before you consider USB, check out the difference between RS232 and RS485. Conceptually similar, but RS485 uses LVDS. When you're ready for USB then, you can tackle the higher speed and protocol overheads.