If you're conducting a multi-page survey, a progress bar will automatically show under the Next page button. It tells your respondent which page he is on and how many pages left to go. If you don't want to show it to them, go to Display Options page and select [Hide progress bar].
By default, respondents can't go back to previous page once they hit Next page button. If you want to allow them to go back and modify their answers, unselect [Hide previous page button] on Display Options page.