You will find generally three subtypes of cookies in this category.
One, Advertising cookies: these are cookies that enable the site owner to manage the advertising space on the web page as efficiently as possible; for example changing ad content based on general trends.
Two, Behavioral cookies: these are cookies that attempt to optimize advertising space available on the basis of your interactions. These cookies store information on user behavior from continued observation of user browsing habits, thus enabling the development of a user specific profile mostly for the purpose of showing advertising.
Three, Tracking cookies: these are cross site tracking cookies from global advertisers. They attempt to form pattern and build profiles on users to maximize interaction outcomes. Commonly introduced via Facebook or Doubleclick services.
A site should be able to provide services without the use of Advertising and Marketing cookies. However, if the sites revenue model is based on advertising, the site may refuse service to you if you disable these cookies.