What are cookies
Cookies are small text files that are placed on your computer by website that you visit. They are widely used in order to remember some useful information such as information related to login which makes the websites work more efficiently and can contribute to ease of use when navigating a website.
Why do we use cookies
The main reason behind why we use cookie is to maintain the session when you navigate between cross origin subdomain. This helps us to log into secure area of our website.