Question

What is the importance of setting or unsettling the cookies deta

Answer 1

Cookies stores small amount of data in the computer related to specific website and be accessed by the server as well as the client . for example if you have to load ha website the cookie will store the data in the website and then show you . If you have disabled cookie then the page will not load.
It is extremely important to regularly  clear the cookie in order to remove any chance of hacking and keep your privacy safe. And also clearing data of cookies will result in faster internet loading.