Device independent refers to the property of a program or system that will run on different types of devices regardless of the operating system or native language of the device. In the world of computing, this is a relatively modern contrivance, because for decades programs were very much dependent on the device or operating system on which they ran. As a matter of fact, early computers were built entirely to run a single program.
One of the earliest and longest lived examples of device independence is hyper-text markup language (HTML). A relatively simple text document with a handful of embedded tags allows any computer with browser software to display it as the author designed it. Many extensions to HTML, such as Java, also are device independent, and others will work only on certain browsers.
More examples of cross-platform or device independent files are all of the modern image formats, such as Joint Photographic Experts Group (JPEG or JPG) files, Tagged Image File Format (TIFF) files and Graphics Interchange Format (GIF) files. These allow any computer to display the images without having to create a new format for each device. A photograph on the screen of one brand of desktop computer will load and display just as well on any other brand of desktop computer or laptop.
Perhaps the most prolific example of device independence is the Adobe® portable document format (PDF) file. These files have become the standard for storing, transferring and displaying documents across all types of systems because of their portability and independence. A PDF will look the same no matter what device it is displayed on or what software is used to display it. Many organizations and governments have standardized on PDF files. One of the largest libraries of PDF documents is perhaps the United States Internal Revenue Service, which has put every form, document and instruction book in PDF format on its website for downloading.
This same device independence extends to all of the new smart phones and third-generation (3G) and fourth-generation (4G) devices so that they are as capable of displaying HTML, photographs, PDFs and other cross-platform file formats the same as the earlier desktop and laptop computers. The outlook of device independent applications is very bright. Where at one time there were only two major operating systems and a handful of browsers, the number of operating systems is proliferating exponentially. As more and more smart devices are released, with many different operating systems involved and apps becoming the software of the next decade, device independence will become critical for success.