Computer also Have revolutionized the way that companies operate, Telephone companies use computer to find the best routing for long-distance calls. Travel agencies use computers to peruse airline schedules and fares, check hotel offerings, and reserve rental cars. Music companies use computerized recording and reproduction technologies to make taps and CD-ROM of your favorite singers. Hospitals use CAT scans (Computerized Axial Tomography) to give physicians detailed looks. Inside a patient’s body. Flight schools use computers during flight training, to let student pilots experience simulated crashes, mechanical failures, and other emergency situations.