A first-party cookie is a type of cookie that is set by a website or app that a user is visiting, and that is only accessible to that website or app. First-party cookies are typically used for purposes such as tracking user preferences, maintaining user sessions, or personalizing content. First-party cookies are different from third-party cookies, which are set by a domain other than the one that a user is visiting, and which can be accessed by multiple websites or companies. First-party cookies are considered to be less intrusive and less risky than third-party cookies, as they are only accessible to the website or app that sets them, and do not involve the sharing of personal data with third parties.