Portable Document Format (PDF) is a file format used to present and exchange documents reliably, independent of software, hardware, or operating system. Invented by Adobe, PDF is now an open standard maintained by the International Organization for Standardization (ISO).
Some device drivers communicate directly with a device, but others are layered together. In these situations, a program will communicate with one driver before that driver communicates with yet another one, and so on until the last driver actually performs the direct communication with the hardware.
With that information, the software also scans for the way to delete the malicious software. Once the scan is complete, the program is prepared to impede the entry of malware on a computer system or destroy it, if it is already on the system. The Firewall. Once the virus database is updated, McAfee Antivirus software strengthens a computer's firewall.
Middleware, computer software that enables communication between multiple software applications, possibly running on more than one machine. Computer applications and Web sites frequently employ many different programs, often running on different computers, that need to work together.
An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.
Most operating system shells are not direct interfaces to the underlying kernel, even if a shell communicates with the user via peripheral devices attached to the computer directly. Shells are actually special applications that use the kernel API in just the same way as it is used by other application programs.
Utility software helps the user to control, manage, and maintain a computer's operating system, hardware and application software. These programs are designed to perform specific functions like finding files, backing up data, playing multimedia files, viewing images and so on.