This is an introductory text for a basic computer literacy course. We have tried to include all of the material necessary for an introductory computer literacy course, but, in order to keep a low price for our students, we have attempted to include ONLY what would be important in such a course. Contents of the text include: 1. Introduction: History of computer development, Different classes of computers, Networks and communication, Virtual reality, Information processing cycle, Distinction between hardware and software, Social effects of computers, Hacking and malware. 2. Computer Components: CPU, Memory, Secondary storage, Input, Output and Communications devices. 3. Computer Software: System software (operating systems, utility programs), Application programs, Classes of and distribution methods for software, Ethical issues related to software. 4. The System Unit: Motherboard, CPU, Types of Memory, Secondary Storage, Data representation, Connecters and Ports. 5. Input: Keyboards, Scanners, Pointing devices (mouse, trackball, touchscreen, ...), Speech recognition. 6. Output: Monitors, Projectors, Wearables, Printers, Fonts, Audio output. 7. Storage: Hard disk drives, Optical storage, Obsolete media, Cloud storage, Data compression 8. Networks and Internet: Internet development, Internet services (WWW, e-mail, FTP, ... ), e-commerce, Internet architecture (HTML, TCP/IP, routers, servers, ... ), Social issues, Security, Net neutrality.The 2020 edition has several new topics and several topics from earlier editions have had information significantly updated. These topics include: virtual reality and haptic technology, smart tv's, videotelephony, VPN's, neural networks, social networks in politics, dark web, WIFI encryption, social engineering.