PHPSESSID: This is what's known as a temporary session cookie. It does not store any personal information about the user and it is deleted when the user closes the browser. The purpose of this cookie is to store information from one page to the next. An example of this would be a success message after a contact form has been sent.
Cookies are small files saved to the user's computer's hard drive that track, save and store information about the user's interactions and usage of the website. This allows the website, through its server to provide the users with a tailored experience within this website. Users are advised that if they wish to deny the use and saving of cookies from this website on to their computers hard drive they should take necessary steps within their web browsers security settings to block all cookies from this website and its external serving vendors.