The personal computer has undergone drastic changes with the introduction of advanced computer software and hardware. The evolution of computers did not develop on its own; Influential key figures such as Steve Jobs and Bill Gates have led the technology revolution. These well-known figures competed with each other by continuously innovating and creating increasingly advanced technologies. Computer technology made leaps forward when Intel created 64-bit technology and advanced kernels to complete the upgrade of processing power. Not only is the evolution of computer technology itself relevant to modern study, but through this revolution has been brought about the adoption of computers for use in other fields of study, such as engineering and architecture. The evolution of a simple concept expanded the scope of the personal computer due to competition between companies trying to control the market. By fighting each other for dominance over which company was best, computer companies changed how society interacted with each other and implemented the personal computer into other forms of study such as Science Technology Engineering and Mathematics (STEM); this was made possible thanks to the development of computer hardware and software. The major contribution to the innovation of the personal computer was not made by a single person, but was the byproduct of competitors in the world of technology. The best-known battle between companies over technological innovation would be the one between Apple and Microsoft. Since the development of the first personal computer, Apple and Microsoft have fought for dominance of the computer market. Microsoft's "Windows Operating System" is the most used operating system in the world. York: Macmillan Reference USA, 2010. Gale Power Search. March 5, 2014. “Hard Drive.” Informatics. Gale, 2007. Gale Power Search. Web. 19 February 2014. “Parallel Processing.” Ed. Roger R. Flynn New York: Macmillan Reference USA, March 17, 2014. “Random Access Memory.” Gale, 2007. Gale Power Search, March 17, 2014. “Supercomputers,” Ed. Roger R. Flynn. 2002. Gale Power Search Web, March 17, 2014. “The Story of the Intel® 4004.” Intel Corp. Intel Museum 2014.