Thursday, 21 October 2010
When you visit a Business, such as say, Google, I am sure that you have to sign in, tell them where you want to go, who you want to see, and possibly, why you are there. In most cases, they will give you an ID Tag, with 'Visitor' on it, and sometimes, a number. That way, Google knows how many visitors they have on-site at any time, and that they have to account for them all, at day's end. That's general practice.
It also tells Google where they can find you, if needed. It also tells them who went where, with whom, and helps, overall, with their security. In that case, if all went well, and you didn't cause any problems, Google will know you are an 'OK' person, if you ever decide to come back. If you don't come back, for a long time, maybe you'll have to show Google that you're an 'OK' person all over again, because they may scrap records after a certain time period. Maybe not. That's kewl. No major issue there. Your Visitor record is either a Temporary, or Permanent thing.
If your visit is a Regular, or Permanent arrangement, say every day, week, month, or whatever, Google will most probably give you a different status, if they have such a thing. Maybe, 'Regular Visitor', or your 'Own' ID Tag, with your Photo imprinted on it, name etc, would mean you just clip your ID Tag on yourself, somewhere, and proceed to your destination. Possibly, no sign-in required by you. That would be a Permanent thing. That would be great, in a Utopian world. I'm sure Google would maintain a different kind of record of you, and your visits.
A Computer Cookie is a text file, or, for the sake of this post, an ID Tag, which is stored by a Website, in your computer's Browser (Temporary), or Hard Disk (Permanent), and in it's own database. It is a way of keeping track of, and a record of, information. It may be of any nature - Name, Age, Gender, Race, Religion - whatever. This is one bad-side to Cookies, called Web Profiling, however, this post is not concerned with that aspect of Cookies.
Temporary Cookies, or 'Session Cookies', are Browser-stored ID Tags, which are deleted when you close your Browser. They work only for a limited time. A Cookie is also a 'Door-Key' that saves the Website from having to re-recognise you when you go to a different page, as it would have to do without Cookies. A Temporary Cookie was created to solve this problem. A record of your visit is also kept by the Website. It tells the Website who you are, what pages you see, so that during your visit, you'll be constantly recognised, and not be kept waiting 'by security', so to speak. This saves a lot of Server time. When deleted, by closing your Browser, these Temporary Cookies are lost, and will have to be re-established next time you visit that site.
Permanent Cookies, also known as 'Persistent Cookies' are different, in that they are stored in your Hard Disk, not in your Browser. They are a 'Permanent' record. The reason for this is so that, even years from now, the Website Server will recognise your ID Tag (Cookie) and, comparing the details for a match, 'open' the door for you. This type of Cookie saved a lot of Server time and effort wasted by re-recognising Visitors - which required re-connection to a site, each time a new page was visited.
After much outcry from the Public, a change was made to the Cookie Technology. It became possible to turn-off Cookies. This was not possible when Permanent Cookie Technology first appeared, around 1995. It also became possible to create an 'Exemption List' of 'Allowable, or Good Cookies'. This also allowed control of 'Third Party' Cookies.
see also: Wisegeek.com