Firefox is a web browser just like Internet Explorer. The difference in my opinion is the performance and the options. They are known for avoiding the security issues that Internet Explorer has.
Firefox has long had the 'tabbed' browsing ability, whereas you can switch between tabs rather than windows. Nice feature because you have everything in front of you instead of a bunch of separate iterations of Internet Explorer running (hence performance). The title of this post will take you to Firefox's home page. Internet Explorer just went to 'tabbed' browsing with IE7.
Firefox also has add-ons called extensions. If I tried to use all of the ones I like or am interested in I probably would never leave my computer. One of these extensions is called DownThemAll or as I call it DownLoadThemAll. As a side note, adding too many extensions has shown me some performance degradation. Of course it may just be my computer. How many is too much? It depends, for me I have 14 extensions loaded. :o)
DownThemAll allows you to right click on a page and down load to a folder specified by you, any file type you want. In my first post I mentioned using zip files. In this case you could right click, select DownThemAll, select 'zip' and start. This avoids having to down load them one at a time. While they are downloading you can leave comments or keep on surfing. In the case of links such as 4share, you can download the links but because they are on a separate site, you cannot download the files.
I learned to use this when collecting fonts. Think about it - 20 fonts (zip files per page). Yikes - definitely carpel tunnel syndrome waiting to happen.