ABSTRACT
ABBREVIATIONS API: Application programming interface CAPEX: Capital expenditure CAPTCHA: Completely automated public Turing test to tell computers
and humans apart IaaS: Infrastructure as a service IT: Information technology MMPOG: Massively multiplayer online games NIST: National Institute of Standards and Technology OPEX: Operational expenditure PaaS: Platform as a service QoS: Quality of service RAID: Redundant array of independent disks ROI: Return on investment SaaS: Soware as a service UPS: Uninterruptible power supply WPA: WiFi protected access
6.1 BEFORE CLOUD COMPUTING e computing world has not always been so practical, powerful, and handy as it may be the case today. First generation (1945-1958) and second generation (1958-1964) computers were mostly huge systems. Examples of rst-and second-generation computers are displayed in Figure 6.1 and Figure 6.2. ey were owned by corporations, universities, and other big institutions. ey could not be used by common
persons because experienced skills were needed. However, there was no direct human-machine interaction. Users prepared tasks for the computer using cardpunches. ese cards contained instructions for the machine and were processed in a batch mode. When the job was done, users had to collect the output. It could take days, even weeks between a job assignment and the retrieval of results.
