CompTIA A+ Core 1 - All Domains

Domain 1: Mobile Devices — 15%

Mobile devices aren’t just smaller desktop computers. Laptops, tablets, smartphones, and wearable devices use specialized components, compact designs, wireless connections, and repair procedures that require a different troubleshooting approach.

You’ll need to understand laptop hardware, batteries, displays, cameras, antennas, keyboards, docking stations, accessories, and common field-replaceable components. Study how mobile devices connect through Wi-Fi, cellular networks, Bluetooth, hotspots, and synchronization services. Pay attention to symptoms such as swollen batteries, damaged charging ports, failed screens, weak wireless signals, and unavailable mobile data. The exam may combine physical repair with account configuration, connectivity, application support, or data-transfer requirements.

Domain 2: Networking — 20%

Networking questions often describe the symptom without directly naming the failed protocol, service, or device.

You’ll need to understand common TCP and UDP ports, IP addressing, DHCP, DNS, VPNs, wireless standards, network devices, cabling, and basic small-office or home-office configuration. Build a clear mental map of what each component does: DHCP assigns addresses, DNS resolves names, switches connect devices within a network, and routers move traffic between networks. Watch for similar-looking answers that use the correct technology in the wrong layer, frequency band, or situation. Slow wireless service, duplicate addresses, failed name resolution, and unreachable resources each point toward different causes and troubleshooting actions.

Domain 3: Hardware — 25%

Hardware questions test whether you can select compatible components and assemble a system that meets the stated workload.

You’ll need to understand motherboards, processors, memory, storage, power supplies, cooling, expansion cards, cables, connectors, displays, peripherals, and printers. Don’t memorize each component in isolation. Consider how socket type, form factor, interface, power requirements, thermal limits, and available expansion affect compatibility. A faster component won’t help if the motherboard, power supply, bus, or cooling system can’t support it. Study printer technologies and maintenance procedures as well, including common image defects and replaceable components. The exam rewards practical component matching rather than choosing the most expensive available option.

Domain 4: Virtualization and Cloud Computing — 11%

Virtualization and cloud services separate workloads from the physical systems supporting them, but the technologies don’t all solve the same problem.

You’ll need to understand virtual machines, hypervisors, containers, virtual desktops, shared resources, cloud deployment models, and service models such as IaaS, PaaS, and SaaS. Pay attention to who manages each layer and where applications, operating systems, storage, and data are located. A remote resource isn’t automatically a cloud service, and a container isn’t simply a lightweight virtual machine in every respect. Study use cases involving scalability, metered usage, rapid provisioning, sandboxing, synchronization, and resource pooling. Trace the responsibilities of the provider and customer before selecting an answer.

Domain 5: Hardware and Network Troubleshooting — 29%

Troubleshooting is the largest Core 1 domain, and the order of actions matters as much as the final repair.

Start by identifying the problem, questioning the user, reviewing recent changes, establishing a theory, testing that theory, planning the fix, implementing it, verifying full functionality, and documenting the result. You’ll troubleshoot storage failures, boot issues, overheating, display problems, printers, mobile hardware, wired connections, and wireless networks. Learn to interpret clues such as beep codes, SMART warnings, link lights, graphical artifacts, print defects, intermittent connections, and IP conflicts. Don’t replace components randomly. The exam often provides several technically possible actions, but only one represents the safest and most logical next step.