The difference between find and filter in jquery method

When writing the front page, often use the Find method in jquery to look for the elements we want, then jquery also need a method filter also has the function of filtering elements, then what is the difference between the two. An example is provided:

<div class= "CSS" >
    <p class= "Test" > I am find</p>
</div>
<div class= "Test" >
    <p> I am filter</p>
</div>
var $find =  $ ("div"). Find ("test");
    Alert ($find. HTML ());
var $filter = $ ("div"). Filter ("Test");
    Alert ($filter. HTML ());

When the page is loaded, you can see the pop-up content, one is: I am find, one is: I am <p> I am filter</p>;
The Find method is a subset of its operations, and filter is the operation of its own elements