What is jquery one function?

jQuery one() is a function which provides single-use event handling. By single-use I mean that the event will be executed/handled only once.
For Example:

$('YOUR_SELECTOR').one('click', function(){
     alert('1. This message will be displayed only once.');
});
http://api.jquery.com/one/

Interestingly the same functionality can be executed by jQuery on() function , as follows:

$('YOUR_SELECTOR').on("click", function(event) {
    alert('2. This message will be displayed only once.');
    $(this).off(event);
});
http://api.jquery.com/on/


Thank You,