Xml assertion is used to check faulty xmls.

Make a http req with server name www.w3schools.com in any thread group

In the path type /xml/note.xml

Add a xml assertion to the request

Run the test and xml assertion will pass and assertion is well formed.

Xml schema assertion -In this assertion we can compare a local xml scehma file to a online xml link and check if online link follows schema rules of our local file.