Cookies, Frames, and Plug-Ins
Sooner or later you will be asked if you want a cookie or the no-frames version of something, or will be told that you need a plug-in in order to view the site or play the game. What should you do?
Cookies: Unless your browser is set to always accept cookies, you will eventually be asked if you want one. Now, if you say "Yes," no one is going to mail you a dozen macadamia white chocolate, or even send you a picture of one. Since HTTP is a "stateless" (non-persistent) protocol, it is impossible to differentiate between visits to a web site, unless the server can somehow "mark" a visitor. This is done by storing a piece of information in the visitor's browser. This is a cookie.
A cookie is a file that is placed on your computer. It allows a web server to store information about you, and then retrieve it in order to identify you in the future. Cookies can store database information, custom page settings, or just about anything that would make a site individual and customizable. It keeps track of things such as the pages you've visited, the items you've put into an online shopping cart, or your user name and password. It is simply an HTTP header that consists of a text-only string that gets entered into the memory of a browser. This string contains the domain, path, lifetime, and value of a variable that a website sets. If the lifetime of this variable is longer than the time the user spends at that site, then this string is saved to a file for future reference.
There are mixed opinions on cookies. Cookies cannot be used to get data or view data off your hard drive. They do not give anyone access to your computer or any personal information about you unless you have given that information to the web site by answering questions or filling in a form. It cannot give your computer a virus since it is a simple piece of text. It is not a program or a plug-in. It cannot access your hard drive. Your browser (not a programmer) can save cookie values to your hard drive if it needs to, but that is the limit of the effect on your system. And only the site that created the cookie can read it.
Both Netscape and Internet Explorer limit the number of cookies that will be saved on your hard drive at one time. Netscape limits your total cookie count to 300. If you exceed this, the browser will discard your least-used cookies to make room for the new ones. Internet Explorer saves cookies into the "Temporary Internet Files" folder, a system folder that you can set the maximum size of (the default is 2% of your hard drive). In any event, remember that the average size of a cookie ranges from 50-150 bytes. You would need about 20 million cookies to fill up a 2GB drive.
Cookies can represent a loss of privacy. As with everything else about the Internet, you are only as anonymous as you want to be. Unfortunately, any time you reveal any kind of personal information about yourself, you are opening the door for that information to be spread. The very nature of Web servers allows for the tracking of your surfing habits alone, and other information about you can be gathered with time. While cookies themselves are not gathering that data, they are used as a tracking device to help the people who are gathering that information. As information is gathered about you, it is associated with the value they keep in your cookie. However, the only way that information about who you are, what your income is, or where you live could end up in a cookie is if you provide it to a site and that site saves it to a cookie. Remember, even without the cookie, any time you visit a web site, that site can determine your service provider, operating system, browser type, CPU type, and your IP address (this changes every time you log on).
You can change the settings in your browser regarding cookies. Look through the menus and the Preference or Options choice to change the setting. Usually you can disable all cookies, accept all cookies, or have the browser warn you before accepting a cookie. However, if you refuse to accept cookies, some sites will not allow you access. And, clicking through all the warnings is tedious. Once a cookie is rejected, it is thrown out and not saved to memory or disk. Don't forget, though, that servers will keep looking for the cookie (even if you have discarded it) and may try to replace it as you surf around. Essentially, without a cookie to tell the server who you are, it can't remember not to send you any cookies.
You can delete all of the cookie files that are already on your hard drive. In most versions of Internet Explorer, the cookies are found in a cookie folder inside the Windows folder. You can delete everything in the cookie folder without harming anything else in your computer. Most versions of Netscape keep cookies in a file in the Netscape folder called cookies.txt or magiccookie on the Mac. You can delete the contents of this file regardless of the warning at the top of the page. If you cannot find the cookie files or folders, use the find option on the Start button in Windows 95/98, or use Finder on the Mac to locate the files. In order to do this properly, remember to close your browser first. This is because all your cookies are held in memory until you close your browser. So, if you delete the file with your browser open, it will make a new file when you close it, and your cookies will be back.
Remember that deleting your cookie file entirely will cause you to "start from scratch" with every web site you usually visit. So it may be preferable to open the cookies.txt file (in the case of Netscape) and remove only the entries you don't like, or go to the cookies folder (in the case of Internet Explorer) and delete the files from servers you don't want. Many sites use a cookie to keep track of your settings on their servers, and to help you log in to their site. If you lose your cookie, that site cannot recall your settings for you to use, and you may not be able to log onto it. If this happens to you, the best thing you can do is contact that site's webmaster or customer service department.If you have a site that is telling you to turn on cookies, but they are on, there are three likely possibilities. First, the site you are visiting may not be detecting cookies properly. As a result, it may appear to the site that you are rejecting cookies when in fact you are not. Second, you may be running software that interferes with cookie usage. There are many filtering and blocking software packages available for Internet users these days, and many of them also filter cookies. If you are running software like this, then your computer may not receive or send cookies. This will cause sites you visit to assume you are not accepting cookies. Third, your machine may be behind a firewall or proxy server that prevents cookie transmission. This is most likely in a corporate environment. So, regardless of how your browser is set, cookies won't be sent or received by your browser. Since the cookies aren't making it through to your browser, the Web Site will assume you personally aren't accepting them.
Occasionally, you may get a cookie from a site you have never visited. A server cannot set a cookie for a domain that it isn't a member of. However, almost every Web user has gotten a cookie from "ad.doubleclick.net" at one time or another, without ever visiting there. DoubleClick and other advertisers have employed a clever solution that enables them to track users and serve media content without violating this rule. Most sites on the Internet do not keep their advertisements locally. Rather, they subscribe to a media service that places those ads for them. This is accomplished via a simple HTML call to the media service. When a page is requested, it is assembled through many HTTP requests by the browser. First, there is a request for the HTML itself. Then, everything the HTML needs is requested, including images, sounds, and plug-ins. The call to the media service is an HTTP request for an image. Once the request is made to the media service, it can return more than just an ad. It can also return a cookie. Or, if it has given the user a cookie previously, it can read that first, and check to see what ad to send. The net result is that the user gets a cookie from the media service without ever having visited it.
Sometimes your Internet Explorer cookies may have your username on them. Because Windows systems allow more than one user to login and use programs, Microsoft had to come up with a way to keep each user's cookies separate on a given machine. This can be common in workplaces, where a single machine may be shared by many employees. This is accomplished by appending the username to the cookie file name. This way, two different users can get cookies from the same site and they don't get over-written. Also, the users won't use each other's cookies while surfing, since the browser will only use the cookies of the person who is logged in. The username does not get sent to the server with the cookie data.
Frames: Today's Web browsers allow site builders to divide the browser window into multiple, scrollable regions called frames. Each frame is filled with a distinct Web page. You can click on a link in one frame to load pages into the other. This can improve and simplify site navigation since you can quickly get to any other part of the site by clicking on a link in the "link" frame. However, older browsers can't handle frames. So if a site needs to be accessible to users with older browsers, there is a separate, "no-frames" version -- essentially, a separate site. The other options that web developers have are to not use frames at all, not allow all users to view their site, and to force the users to upgrade. Hence the two-site no-frames option.
To a web site developer, frames can work to your disadvantage. Because the URL stays the same as you navigate a framed site, bookmarking individual pages can be tricky. So users may have trouble getting back to a specific page in your site. If you're using Netscape Navigator 2.0 , Microsoft Internet Explorer 3.0, or AOL Web browser 3.0 (or more recent versions of any of these) you can view frames and shouldn't have to worry about it
Plug-Ins: Often, when trying to access something really neat on the Web, you will be told the thing you want needs something on your computer in order to run -- and that you need to download it. You may be trying to play a game, or watch a news clip, or listen to some music. This combination of sound and action is called multimedia. To experience multimedia online, you should have a computer with a sound and video card. Then what you need are special pieces of software called plug-ins. A plug-in extends the capabilities of your web browser, like Netscape Navigator or Microsoft Internet Explorer, turning your computer into a radio or television.
A plug-in is like an attachment to your browser. The technical definition of a plug-in is a small add-on piece of software that conforms to Netscape Navigator standards. Other browsers however, including Microsoft, support many Netscape plug-ins. But Internet Explorer actually uses a different software standard, called an ActiveX control, instead of plug-ins. And there are plug-ins for Navigator that allow it to run some ActiveX controls.
Essentially, though, it is a piece of software that has been created by third-party software developers. Each one performs a specific function, so you may need to download several before you are done. However, you only need to download the plug-in that performs the function that interests you. When you try to access a file that requires a plug-in -- like a sound or movie -- the necessary plug-in launches automatically. Most browsers now come pre-packaged with the most popular plug-ins, and users can acquire the additional ones they need as they go along. (If you don't have the required plug-in, you're usually asked if you want to download it right then and there.)
If you are a Netscape Navigator user, you should have (or should create) a directory or folder on your computer for downloading files over the net. The C:\Temp folder. Once you have installed the plug-in, you can easily delete the downloaded install files. Navigator plug-ins have to be downloaded and installed. If you go to a web page that contains a file requiring a plug-in that you don't have, you will usually get a message asking if you want to get the plug-in. If the page is set up properly, clicking the "Get Plug-in" button will take you to the web site of the plug-in maker. There you can download the plug-in.
All Navigator plug-ins need to be installed. The general procedure to download and install a plug-in is to download the plug-in file to a temporary directory that is empty, close all running applications on your computer. and double-click on the file to install it. Most of the time the installation will be automatic. Occasionally, you will run into a downloaded file that needs to be decompressed before installation. If double-clicking produces an MS-DOS window or puts more files into the folder, you should look for an install.exe or a setup.exe file and double-click on that.
If you are a Microsoft Internet Explorer user, Microsoft designed ActiveX so that controls will install automatically when you get to a web page that contains a file needing an ActiveX control. For controls set up this way, you may get a warning message telling you that a control is about to be installed. Other than that, the control installs and plays the file without you having to do anything. Many multimedia controls still need to be obtained from the developer, but are installed automatically. Shockwave is a good example of this. All you need to do is go to the Macromedia site with Internet Explorer and click on the link to install the ActiveX control. The rest happens automatically. The next time you go to a "Shocked" website, the Shockwave control loads and plays the movie.
As mentioned earlier, some Navigator plug-ins are designed to work with Internet Explorer. Those may need to be downloaded and installed into Internet Explorer using the same procedure described for Navigator users.
Another term you may run into is streaming. "Streaming" means that you don't have to download an entire file before the audio and video begins to play, so you get the media faster. For streaming to work, your computer (the one receiving the data) must be able to collect the data and send it as a steady stream to the application that is processing the data and converting it to sound or pictures (that's your browser). This means that if your computer receives the data more quickly than required, it needs to save the excess data in a buffer. If the data doesn't come quickly enough, however, the presentation of the data will not be smooth.
Many plug-ins and controls can be downloaded for free over the Internet, although not all will work with every system. Some of them, for instance, only work with Windows 95. Here are a few of the more popular ones:
You can find an exhaustive list of Navigator plug-ins and ActiveX controls at Browser Watch. Check out either ActiveX Arena or Plug-in Plaza.
For a list of other sites you can hear and view in real time over the Internet, check out these sites:
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