Our today's topic is what is Vob file. At this present updating world the uses of computer become wider. But when we use computer for different purpose such as storing some data in a database or to listening music, files are used to do the required job. Now there are a number of file formats are present to store different types of information such as text, video, audio etc. The content of a file may be printable or unprintable. Generally unprintable files are known as binary file. We use many special kinds of unprintable file formats to store a video or audio in a computer system. But to transport data from one system to another, external storage devices are required. In early age, many external storage devices are used such as floppy, zip, compact disk or CD etc. But, at this modern era a new external storage device is invented. The name of this device is DVD. It has a high capacity to store a large amount of data. In DVD, a special kind of file is generally used to store video. The name of this special file is vob file. This file can be identified by its extension that is .vob. This kind of file is used to store subtitle, video, audio and menu in a DVD. It stores these types of data by multiplexing them into a large stream. This file is exists under the group of MPEG, that is a group which is generally known as Master Pixel Experienced Group. In a DVD, to multiplex different items of movies, MPEG-2 videos are generally used which can serves a clear picture quality with high resolution. A number of DVDS writing software are available in the market. Some of them are nero burning ROM, DVD burner etc. But they only support the vob file to write videos in a DVD. Many of them convert any type of video to vob format before writing it on the DVD. The name of this file that is vob is used to represent video objects. The advantage of using this type of files are, it serves good quality pictures as well as videos with high resolution, it has the capability to make a DVD copy protect and it can handle a large video stream without any interrupt. An encryption process is used in case of DVD to make it copy protected with vob file. This encryption is known as Content Scramble System. The use of vob file becomes wider now.