So, "What's a cookie?" I hear you ask!
A cookie is simply a piece of information that the web browser stores about some aspect of the website that's specific to the current visitor. The cookie is stored on the visitor's computer, and is remembered between visits to the website. Cookies are useful for the developer of the website and can be used to enhance the visitors experience.
For instance, a cookie could contain information about the name of the currently logged in user, or what size font is the preferred size to view the website, or which page on the website was last visited.
The second change that's been made has been to the Contact Form.
Unfortunately, the website has been receiving increasing amounts of SPAM e-mail lately. SPAM e-mail is usually sent by unscrupulous people trying to solicit personal information by sending the unwitting recipient to a Phishing website or to a website containing Malware.
SPAM e-mail's are usually generated automatically using a piece of code known as a Spambot. In effect, this means that there is no human interaction occurring with the contact form. Spambots can send thousands of e-mails and really inconvenience a website operator if they are targeted.
To combat the Spambots, there is now a cool bit of technology provided by Google, called a reCAPTCHA. This requires that a human be present at the keyboard when the contact form is submitted. Unfortunately it means a few more clicks for the genuine visitors, but hopefully it won't inconvenience anyone so much that they won't bother to get in touch.