PDF, which is an acronym for portable document formant was initially developed by Adobe Systems beginning in 1993. Its primary purpose was to represent two dimensional documents in a way that was independent both of the device and the display resolution. a pdf file can typically be read by most web browsers on most devices. PDF files include the complete description of either a two-dimensional or with Acrobat 3D, three-dimensional documents. Currently pdf files are considered open standard. Preparation for submission as an ISO standard is in process. Over the years, pdf files have become the accepted way of capturing and storing two and now three dimensional images. Governmental jurisdictions, colleges and university research archives, medical records and many other applications have been converted to pdf files so that full retention is available and searchable. This allows massive amounts of information to be protected and stored in much the same way as microfiche and microfilm used to be retained. However, the use of the computer for preparation and storage of the files means that almost anyone with a desktop has access to the information. No longer is it necessary to have a bulky microfiche or microfilm reader in order to view the images. How this search engine works and its benefit? Its function initiates when a user enters relevant keywords of the topic on which a file is to be viewed and then by clicking on search you get links relating the theme. There is loads of data on such links. At times, it as well functions as a utility for searching eBooks since any eBook that has been submitted in pdf format can be easily located through it. The main benefit of using it is that it is strongly immune to viruses and bugs therefore downloading any such program is safe. A majority of them do not make it mandatory to register so there is an easy access to them for any user.Selecting your online PDF searcher keep in mind that if you want to get something worthwhile reading, it requires a certain measure of commitment on the other end (i.e. the authors); so, expecting commitment is good but also be ready to give a commitment in return.