A security application is a type of program that protects the user from threats that may harm the host computer or device, often through an Internet activity such as visiting a website, downloading a file or opening an email. These programs detect the threat, known as a virus, and remove it so that it no longer harms the computer.
Most security applications feature an online and offline component, with the online aspect actively checking the websites and Internet actions of the user for threats, while the offline aspect scans the computer looking for any type of malicious software. The application typically functions as a single program that runs in the background any time the computer is active, though it may also install special components on the computers Web browsers to help prevent access to potentially harmful sites or downloading viruses.
The application may also impose additional precautions that augment or support the security features of the operating system, such as the firewall. A firewall monitors the incoming and outgoing Internet activity between programs on the computer in addition to the Web browser. Though many operating systems feature a native firewall, a security application introduces its own protocols that include access to its database of harmful sites and programs to add a more intelligent and user-friendly level of protection. Some security applications also function on mobile devices, though they include features and functions that differ from desktop computing.