What are cookies?
Cookies are browsing information collected in small text files that a website places on your computer/device. Stored details can include such things as your site preferences or profile information, as well as personally identifiable information (such as your name, home address, email address, or telephone number). However, this information can only be stored if you provide it. Websites cannot gain access to information you didn't provide to them, and they can't access other files on your computer.
Often websites store information needed as you navigate through them, such as what items you placed in your shopping cart. If the site is "trusted" (HTTPS or a lock icon in the URL bar), then cookies can make your visit more convenient -- storing contact details, for example -- as well as enrich your experience as the site learnes your preferences and can offer options customized for you.
Are cookies good or bad things?
Generally they can enhance your browsing experience. However, if the site is not trusted, it could expose personal details and put them at risk. Blocking all cookies could help protect your privacy, but it could also limit your online experience. As with most things, you should always be cognizant of what you're sharing and with whom.
Are all cookies the same?
There are different types of cookies. Temporary cookies (or session cookies) are removed from your computer after you close your browser, such as a list of items in a shopping cart. Persistent cookies (or saved cookies) remain on your computer after you close your browser. One example is a sign-in name and password. Persistent cookies can remain on your computer for days, months, or even years.
There are also first-party and third party cookies. First-party cookies come from the website that you're viewing and can be either persistent or temporary. These are used to store information that they'll reuse the next time you go to that site and are typically critical for site functionality and usability. Third-party cookies come from other websites' advertisements (such as pop-up or banner ads) on the website that you're viewing. Websites might use these cookies to track your web use for marketing purposes. These are the kind of cookies you may want to block.
How do I block or delete cookies?
You will need to set your preferences for each browser you use. What and how you do this will vary with each one, so consult the browser help documentation for directions.