Each browser, and browser version, operate slightly differently. Ifboth your browsers are of the most recent version (e.g. Firefox 3.0 or newer, IE 7.0 or newer), the site should look identical.
All browsers are created by differentcompanies and the companies do not coordinate with each other on whatthey offer. For example some javascript code may be specific only toone browser. As well, older versions of browsers may show a differentfont or change your format although all your content will still bethere.
Fortunately, about 80 to 90% of web surfersare on Firefox or IE and have one of the latest versions. It is free toupgrade both.