Cookies are one of the most misunderstood of web elements. People confuse them with spam and spyware, and even those programs confuse cookies as such.

A cookie is simply a very small piece of data created by the server based on your preferences when you visit a website. It is not an executable program and it can not do or change anything on the individual's computer.

There are two basic types of cookies you will encounter on the web, session cookies and persistent cookies. They do basically the same thing, remember your information during your visit to a website, but have different purposes. A session cookie is placed on your computer to remember your visit and is erased when you leave the website. The server and browser have no memory of your visit if you visit again, another cookie will be placed on your computer temporarily.

Persistent Cookies do basically the same thing, except they are designed to last a short period of time on your computer so a cookie doesn't have to be placed on your computer each time you visit a website.

Cookies are very important in the realm of ecommerce. If your site does not use session cookies, products placed in a shopping cart program would be deleted and gone by the time the customer went to check out. Matter of fact, if someone is writing you telling you that they are unable to use your shopping cart or it isn't working because their items keep disappearing, 9 times out of 10, the problem is that the consumer has their browser set to reject all cookies. Asking your customer to check their browser settings and tell them to temporarily change them to "accept cookies" will usually do the trick.

Last but not least, be sure and state in your online privacy policy statement how you use cookies and if you use persistent cookies, how long they will last.