Published notes can be read by your visitors. Unpublished notes can only be read by you.
Notes submitted on your profile will be automatically published unless you change your settings and choose to publish them manually. To change your settings, click the gear icon 
in the orange bar on the top right corner of any page, select Account and then Privacy. From there, scroll down to the Moderate notes on my profile section and click the oval bar either close to the left hand side of the bar or close to the right hand side of the bar. If the bar is green, then the setting of publishing notes automatically is turned on, and if the bar is gray, then the setting of publishing notes automatically is turned off.
Notes that are unpublished will have a green circle with a check-mark to the right of the note. To publish the note, simply click on the green circle. You can also delete a note by clicking on the trash can icon regardless if the note is published or not.