What are cookies in JavaScript?

Web Browsers and Servers use HTTP protocol to communicate and HTTP is a stateless protocol. But for a commercial website, it is required to maintain session information among different pages.

Using cookies is the most efficient method of remembering and tracking preferences, purchases, commissions, and other information required for better visitor experience or site statistics.

Cookies are a plain text data record of five variable-length fields −

  • Expires − The date the cookie will expire. If this is blank, the cookie will expire when the visitor quits the browser.
  • Domain − The domain name of your site.
  • Path − The path to the directory or web page that set the cookie. This may be blank if you want to retrieve the cookie from any directory or page.
  • Secure − If this field contains the word "secure", then the cookie may only be retrieved with a secure server. If this field is blank, no such restriction exists.
  • Name=Value − Cookies are set and retrieved in the form of key-value pairs