Application Software is used to create files of various types and perform a particular task. For example, Excel is used to create a spreadsheet and perform calculations. Word is used to create a word processed document such as a letter or resume.
Application software  

Browsers can't create files but are built to to display plain text formatted with html tags and display graphics or animations made as .jpg (.jpeg) or .gif file formats. However, they can play or show other file types by using plug-ins. Plug-ins are small executable "players" that extend the ability of the browser so it can play and show files types that weren't made for browser display. Common plugins include Quicktime player, Real Audio and Video, Flash, Java (applets), Adobe reader and so on.

When you use a browser to send a command to a server to get (aka download via ftp) a file, the browser will do one of the following actions:

1. Download, open and "Play" the file
2. Download, open a plugin and "Play" the file
3. Download, open the file's proprietary software and "Play" the file
4. Download, open and offer to "Save" the file 9it can't "Play" it.

Browsers can read plain text documents (unformatted; aka ASCII or DOS), HTML text files (formatted text and clickable text), graphics and image files, sound files, video files, streaming audio and video files, animation files, and PDF files.
(see Interlit Website, Chapter 12 http://www.udel.edu/interlit/chapter12.html

Browsers have applets that will play many types of files besides webpages. Try these:

Sounds | Sounds | Sounds |PowerPoint | jpeg | animated Gif | Gif | program | Motion Picture | program | screensaver install | PDF

Here is a great link to look up file types and the associated software or technology they are created with. FileInfo.com