first-party cookie - Computer Definition
A small amount of text stored in the user's computer that is created by the website the user is visiting. By default, first-party cookies are allowed in every Web browser. If you were to disable first-party cookies, a website could not keep track of your activity as you move from page to page. For example, you would be unable to purchase multiple items online in the same transaction. Each time you added something to the cart from another page on the site, it would be treated as a new order. See cookie, third-party cookie and stateless.