Both ________________ software and application software are essential for accomplishing tasks with a digital device. Today, application software is distributed online. The main executable file for PC software has a(n) ________________ extension, whereas executable files for Macs have a(n) ________________ extension. New versions of software are called ________________ and are indicated by version numbers such as 1.2 and 2.0. A software ________________ or patch is a small section of program code designed to correct problems and address security vulnerabilities. Software pricing models include one-time purchase, ________________ , trial, and freemium. Software licenses, referred to by the acronym ________________ , can be divided into two main categories: public ________________ and proprietary. ________________ software is usually sold in retail stores or at Web sites and may have options for site licenses as well as single user licenses. Freeware is copyrighted software that is available free of charge. ________________ is also available free of charge, but is limited in some way until you pay for it. ________________ is also distributed free of charge but uses the honor system to collect payment. Open ________________ software may be sold or distributed free of charge, but the distribution must include the source code.