Common file standards associated with the Internet
Introduction
There are many different files used on the Internet. We will describe some of them here.
PDF (Portable Document Format)
A PDF file is used on the Internet to let people open up, view and print documents on their own computer, even though they may not have the software themselves that was used to originally make the document. You can think of a pdf document as a photograph of a document because although you can view it, you can't usually edit it unless you have some special software. PDF files have the advantage of keeping all of the formatting in place, regardless of the PDF viewer you are using to view the document. There are many free PDF file viewers that you can download and use and many common word processing applications can view them as well.
JPG or JPEG (Joint Photographic Experts Group)
JPG is a picture format commonly used for photographs and complex pictures, which require thousands (up to about 65000) of different colours and shades. It uses 'lossy compression' so files are small and download quickly with very little loss of picture quality.
GIF (Graphics Interchange Format)
The GIF format is perfect for simple diagrams and drawings, which require only a limited number of colours (up to 256). The files are small and therefore are transmitted across the Internet quickly. They are also used to make 'animated gifs'. These are small animated pictures, often used for 'emoticons', for example. Try searching for 'animated gif' or 'emoticon' and see what you can find.
MP3 (MPEG-1 Audio Layer 3)
This is a file commonly used on the Internet for sound files and voice recordings. It compresses files using lossy compression so the files are small with a small amount of loss of quality, but not noticeable to most people.
MPEG (Motion Picture Experts Group)
This type of file is used on the Internet for video. It uses a lossy compression method, which sends a full picture only occasionally (a few times a second) but sends what has changed since the last time a full picture was sent far more frequently. By using this method, near TV quality video can be sent and streamed across the Internet.