xiii ■ Chapter 5 Power Supplies was streamlined and revised to include information about eSATAp and external power supplies. ■ Chapter 6 Memory refl ects up-to-date information and now aligns to the revised CompTIA Objectives. ■ Chapter 7 Input Devices was revised and updated to include information about NFC, VR/AR headsets, and chip readers. ■ Chapter 8 Video Systems previously discussed both video and audio systems. In this edition, it is divided and appears as Chapter 8 and Chapter 9. In this chapter, the focus is on video systems and video cards. ■ Chapter 9 Audio Systems, which was previously the second half of Chapter 8, focuses solely on audio systems and audio cards. ■ Chapter 10 Magnetic and Solid-State Storage Devices, formerly Chapter 9, was revised and updated to remove discussion of outdated technology and expand fi le systems and disk management information. ■ Chapter 11 Optical Storage Technology was previously Chapter 10. It is largely intact but given a general update and revision. ■ Chapter 12 Printers was Chapter 11 in the previous edition. Th is chapter was revised to include additional information about printer sharing and virtual printers. ■ Chapter 13 Laptops and Mobile Devices, formerly Chapter 12, was expanded to include coverage of mobile devices, smartphones, wearable technology, cloud services, and e-readers. ■ Chapter 14 Modems and Transceivers was previously Chapter 13. Th is chapter is updated to refl ect the revised CompTIA Objectives and to include additional information about mobile broadband connections. ■ Chapter 15 Physical Security and Authentication, which was Chapter 14 in the fourth edition, was heavily revised and reorganized. Th is chapter was divided into Chapter 15 and Chapter 16. Th e content is revised to refl ect technological updates and CompTIA A+ Objectives. ■ Chapter 16 Security Applications and Malware, formerly part of Chapter 14 in the previous edition, now focuses solely on security applications, catego- ries of malware, and malware removal. Th e content has been updated and revised to refl ect new Comp- TIA Objectives. ■ Chapter 17 PC Troubleshooting was previously Chapter 15. Th is chapter was updated to refl ect CompTIA’s revised troubleshooting guidelines as well as include more commonly encountered symptoms and how best to troubleshoot them. ■ Chapter 18 Data Recovery was previously part of Chapter 15. Th is new chapter focuses exclusively on recovery techniques as a separate task from troubleshooting errors. ■ Chapter 19 Introduction to Networking, formerly Chapter 16, focuses on an introduction to basic networking concepts, such as benefi ts, administra- tive models, classifi cations, topologies, equipment, and NICs. ■ Chapter 20 Network Communication, Media, and Tools, formerly part of Chapter 16, now focuses primarily on the means by which networks com- municate, as well as the media and tools used in network installation and troubleshooting. ■ Chapter 21 Network Administration was Chapter 17 in the previous edition. Th is chapter was revised to include updated networking information for Windows 10 and Windows Server 2016, as well as meet the revised CompTIA Objectives. ■ Chapter 22 Wide Area Network (WAN), formerly Chapter 18, now includes coverage of cloud services and meets the new CompTIA Objectives. ■ Chapter 23 Small-Offi ce/Home-Offi ce (SOHO) Networking, previously Chapter 19, was given a general update and revision to meet new CompTIA Objectives. ■ Chapter 24 Customer Support, Communication, and Professionalism was formerly Chapter 20. Th is chapter is updated to refl ect revised standards for documentation of best practices and document types, as well as an expansion of the information about professionalism. ■ Chapter 25 CompTIA A+ Certifi cation Exams Preparation, which was Chapter 21 in the previous edition, refl ects current CompTIA A+ Exam percentages. In addition, both practice tests are updated and mimic the CompTIA A+ Exam in a more realistic way. Questions are no longer organized by domain. ■ Chapter 26 Employment and Advanced Education, previously Chapter 22, now includes information such as soft skills, digital citizenship, and other qualities employers seek when hiring or promoting employees.