The PDF file was actually developed by Adobe Systems during the earlier part of the 90s. An acronym for Portable Document Format, the PDF file's primary purpose was the representation of 2D or 2-dimensional documents in such a way that these would be independent of both device and display resolution. The huge advantage of the PDF file is actually the fact that it can be read by almost all web browsers circulating the industry on most devices as well. And over the years, because of the convenience brought about by the PDF file, sit has actually been one of the preferred file formats used by a lot of industries, such as colleges, medical institutions, even governmental jurisdictions. With all the PDF files existing all around, it becomes a must to know the basics on using PDF search engines. Most websites these days, especially those that offer an array of services, incorporate a brochure in PDF format that can be read by the customer even when he or she leaves the site. Property listings, spa treatment centers, and restaurants often attach brochure files to make customers aware of what they are offering. Keep in mind however that these have to be PDF search engine optimized in order to be more visible in queries. Highly recommended research material is always available in PDF format. For example, all e-books are available in PDF format and the content of electronic scientific journals is always available in PDF format. PDF search engines are alike custom research engines. These search platforms are optimized by keywords and are regularly indexing new files available via Internet. Indexing of files is a regular process for all search platforms like PDF file searching engines. When you use the ordinary search engine to search PDF file, a common problem here is the fact that the files themselves are downloaded as a whole. When you type in words and phrases for the ordinary search engine to find, it would not give you just a chapter or two for each file it would bring back. The whole file would be returned, as long as it contains the word or phrase in question. Imagine how many PDF files would be returned this way! Thus, whether you want to search PDF files in your computer or from the web, then a third-party search engine is indeed ideal to have.