PDF (Portable Document Format) is a special universal electronic document format developed and patented by Adobe Systems Corporation. Created for compact representation, storing important printed documents in electronic form, as well as for opening and printing them on PCs running on different operating systems. Literally translated PDF means " portable document format". In PDF format, you can save information in any form and at the same time it will be displayed the same everywhere.
Today, a format with a similar resolution can be called most popular for the presentation of various printed products.
How to open pdf format
Having an idea of how and with what you can open files in PDF format, users can easily work and view a lot of interesting and useful information.
Among the most popular universal utilities for quickly opening documents presented in pdf resolution, you can Mark:
- Adobe (Acrobat) Reader.
- PDF Viewer.
- STDU Viewer.
- Fox Reader.
Each of the above programs has its own functionality, capabilities, a set of useful options and will help the user open PDF on any personal computer, laptop running on Windows, other operating systems. In this case, regardless of the version of the OS or PC, the documents will be opened in the form in which they were originally created.
Using Adobe (Acrobat) Reader
Adobe (Acrobat) Reader - Universal free an application that is designed to conveniently work with PDF. Using this utility, users can open, view, edit, copy, comment, review, perform other operations with any documents.
The software has quite low system requirements and at the same time it is able to open all existing modifications of the PDF format, allows PC users to work with files through various forms. 
Among main functions this utility can be noted:
By installing Adobe Reader on your PC, users 3D viewing available document content. There is the ability to play various audio and video files, the function of opening electronic books, the option to increase the necessary elements in the text. The program has an intuitive, user-friendly interface. 
If this utility is already installed on your PC, when you open a PDF document, it will be activated automatically. The desired file will immediately be opened in Adobe (Acrobat) Reader.
Using additional services Adobe (Acrobat) Reader, you can create, convert PDF, and also export them in Word, Excel. 
PDF Viewer
PDF-Viewer is an easy-to-use, convenient, secure PDF viewer. Spreads on free basis. Utility intended to view, convert, read, edit, print, any PDF. 
Using PDF-Viewer, users can perform various manipulations with the content of documents. With this utility, you can quickly convert files to other formats(PNG, TIFF. BMP).
After opening the software, you must select, mark and open the desired document. Near the window with files, information about this document will be displayed, which can be called advantage this program.
After opening, the document appears on the screen in a readable version. The program has an intuitive, simple, user-friendly interface, a large selection of settings, additional options. The main advantage of the free utility is that it works quickly not only on any OS, but also on weak PCs.
How to use STDU Viewer
STDU Viewer - universal, very comfortable free utility for working, viewing, editing electronic documentation. The program has a convenient, understandable, simple interface, a large number of useful options (scaling, converting, display modes), simple navigation tools, allowing you to work quickly and comfortably, view the contents of selected files.
Using the STDU Viewer, you can add bookmarks when reading, marking the necessary fragments of the text, turn pages at 90 degrees, view the pages in a turn or one by one. The program can display several pages on the PC screen at the same time, support hyperlinks. Implements Fast passage between pages. When working with electronic documentation, you can change the resolution of the current page without changing the rest.
To get started, run the installed utility. From the menu select " File/Open» or right-click on a free field: 
Going to Settings, you can tick off the necessary items for convenient work with an electronic document.
After pressing the key " Open”, the document opens in readable form.
Opening a document with Foxit Reader
Foxit Reader is a fairly popular, lightweight, fast utility for reading, viewing, working with PDF, various types of electronic documentation. disadvantage programs can be called English speaking interface. At the same time, thanks to a convenient, intuitive menu, it will not be difficult to understand the capabilities of the utility. If necessary, for more convenient work, you can additionally download and install Russifier, which will fully translate all menu items.
The program is distributed free of charge. Works without problems even on weak PCs, does not need installation, regardless of the configuration, version of Windows OS. Foxit Reader respects the security, privacy of users, never connects to the Internet without confirmation.
To open the desired file, run the program on the computer. In the window that appears, select the desired menu item, confirm the action " OK».
We find desired document, open it (" File/Open”), after which the document is displayed in a readable form.