The widely accepted document format on the web would probably be the PDF format. Most documents shared on the web are being converted to PDF format. The reasons behind this phenomenon are the following. You would be able to get the same PDF file no matter where you would want to download the file. There would be no changes done when you get the PDF file. This is a unique property of this file format because it keeps all of its contents as intact as you want it to be. To view these files you will need a PDF reader software. This application is free to download in any website that might host the files. This software is also present in this website and you can download this for free here.
PDF reader application also has some editing tools but are only limited in terms of modification. One of the things you can do with your PDF files with this application is to add certain items such as text and signatures to the files. You would not be able to edit the contents from a standpoint of deleting existing contents. All you can do is to add new content to the files with the PDF reader. The signature addition to the file is much related to the business or official document that you need to sigh with a digital signature. You can insert this in the PDF file. Another thing you can modify in a PDF file with this software is that you can add files and pictures to the file. This will become attachments to the original files. It would be downloaded in the same manner as the original files would be downloaded.
If you are in search of a good PDF reader software you might want to consider these properties. Do not confine yourself to the notion that you can only use this application to view and read PDF files. Some applications presents you with a little more options other that viewing PDF files. These functions would be of some help to you when the time comes. There are things you need to remember about PDF reader applications and the most important probably would be is that you cannot create PDF files with this software. The main purpose of this software is to just give you the option to view PDF files and creation functions are not available for this application.