some general internet type questions

[real_illusions]

on forums, you see the index page is sometimes kept as/forum/index.php?act=idxwhat does that mean? i'm guessing "idx" means index..but why does it show that? why not just "index.php"i've seen some sites have www1.websitename.comwhat is this www1? or www99?? such as http://www99.epinions.com www1 also works with that site but it redirects to www99.thats the only 2 for now..but i'm sure i can find some more :)thanks:)

[reportingsjr]

the index is just to make sure you are actually on the index, and ive also seen the ww2.sitename.com and such, im just guessing thats how they have their domain set up. Im sure justsomeguy or aspnetguy will know..

[justsomeguy]

This type of thing:/forum/index.php?act=idxIs usually to tell a page what to do. 'act' probably corresponds to 'action', the programmer is using a querystring variable to tell the page what to do. This type of thing happens when one page of code is responsible for producing multiple pages of HTML. I created a photo gallery that is entirely contained within one PHP file, and so I use a page_mode variable to tell if the user is at the index, or at a specific gallery, or looking at a specific image, or whatever:index.php?page_mode=view_galindex.php?page_mode=view_imgetc.The different subdomains are usually do to load-balancing. You can see it if you go to www.php.net - click a link and you will be at a different subdomain other than www (usually). This is to keep the balance on the servers at a reasonable level. If php.net has 100 servers behind it to handle all of the requests, it doesn't do any good if people just type in www and you end up with 90% of your users on the same server, with the other 99 servers nearly empty. So, there is a piece of software or hardware that checks the geographic location of the user (or which server is fastest for them), and sends them to an appropriate server. This helps to keep the speed of each individual server up, and it allows the maximum number of users to all be using the same resources at the same time, because they are spread out across the servers. This also happens with mirroring, one server may be set up to mirror the content of another server, and it's another way to keep the load on each individual server to a minimum.Behind the scenes, there is software that keeps the files on each server up to date with eachother.