What is a File?

Files are collections of information. In fact, almost all of the information stored in a computer is stored in a file. There are many different types of files, including operating system files, program files, and your own files.

Different types of files store different types of information. Each file is given a filename and has a three-letterfilename extension that identifies the file type. (The filename and filename extension are separated by a period.) For example, a document created using WordPad might have the file name, letter to John.doc.

Some common file name extensions are:

• doc: Word or WordPad document
• txt: Notepad text file
• eml: Email file
• xls: Excel spreadsheet
• htm or html: HTML file (web page)
• ppt : PowerPoint presentation
• mbd: Access database