If all browsers applied web standards correctly, then every web page would look the same in each browser. Unfortunately, this is not the way it is. Each browser (Firefox, Internet Explorer, etc) supports various standards and displays web pages slightly differently. To test your web pages, you could install a copy of every browser and load it. Or you could visit BrowserShots.org and let them do the work:
Browsershots makes screenshots of your web design in different browsers. It is a free open-source online service created by Johann C. Rocholl. When you submit your web address, it will be added to the job queue. A number of distributed computers will open your website in their browser. Then they will make screenshots and upload them to the central server here.
The screenshots do not appear instantly, but you can bookmark the page and go back to it. The default time period is 30 minutes, but I had to extend the time (there is a button) as it took more than 30 minutes for the screenshots to appear. If you want to see the screenshots for PCIN.net, click here (I’m not sure how long the screenshots will be available for).