Cookies on Your Computer
By and large, cookies are a useful, invisible component of your life online, designed to make it easier for you to get around on the web. However, there are people who find the very idea of them offensive.
What is a cookie?
A cookie is simply a text document that a website can place on your hard drive to store information and then retrieve it later. They aren't capable of gathering any information on their own. Also, they cannot collect information about you from your computer. In fact, most cookies don't do much other than keep some info around about preferences or number of visits and so on.
Cookies cannot deliver viruses to your computer, nor can they be used to run code or computer programs.
There are actually two kinds of cookies. The persistent cookie – the most commonest type – is written to the hard drive of the user’s computer and lasts until the expiry date is reached; the session cookie is kept in the memory of the browser only as long as the user visits the website in question and disappears when that session ends.
The cookie will include minimal details. Without getting too technical, these will include a name, a value, a path specification, an expiry date (if required) and often some security information.
How does it work?
If you type a website address into your browser, your browser sends a request to the website for the page. Your browser will also look on your hard drive for a cookie for the website. If it finds one, it will send the information in the cookie along with the address. If there is no cookie file, nothing is sent to the website address.
If no cookie information has been sent, the website knows that this is the first time you have visited it. It creates a new ID for you and sends it to your hard drive.
Why do websites use cookies?
They can accurately work out how many people use the site because they can tell the difference between new visitors and return visitors. It is useful for websites to know which pages are popular, and how users navigate around their site.
Some websites that require you to log in or register, offer you the chance to be ‘remembered’ so you are logged in automatically on each visit. That’s because the site recognises a cookie set previously on your computer. Cookies also allow such things as shopping trolleys and quick checkout options on shopping sites because they keep track of what you're buying.
Problems with cookies
Cookies are designed to be read only by the website or domain that set them. There have been instances when other domains have been able to access and read them. This might be a concern for the user, whose web-surfing details are thus open to third party scrutiny. It's also a concern to the site that set the cookie. They risk a commercial rival uncovering details of how people use their site.
It is possible for someone with physical access to your computer to copy all your cookies, export that data to another machine and there assume your online identity.
The cookies set by some advertisers will track your web surfing, noting the sites you visit and targeting ads they think you will click on. The danger in this case is to your privacy. This is the main reason some people choose to 'block' cookies on their computer.
Disabling cookies
You have the ability to enable or disable cookies, or have your browser prompt you before accepting cookies: the means varies according to your browser. It is a straightforward, non-technical process. Microsoft describes how to do so on all Internet Explorer browsers and how to manage your cookie settings: If you use a Netscape browser, go to Edit > Preferences > Advanced and follow the instructions form there.
With cookies disabled, you cannot ‘personalise’ a website (i.e. by saving your username and password settings) and you will not have access to all services and functions – shopping online, for example. Surfers who opt for that prefer the peace of mind that comes from knowing the cookies are no longer stored on their computer.
