What does 220-1201 cover?

Core 1 (220-1201) covers five domains: Mobile Devices (13%), Networking (23%), Hardware (25%), Virtualization and Cloud Computing (11%), and Hardware and Network Troubleshooting (28%). It's the hardware-and-infrastructure half of CompTIA A+.

What's the hardest Core 1 domain?

Most candidates find 5.0 Hardware and Network Troubleshooting the hardest — it's the largest domain (28%), it's scenario-based, and it requires applying CompTIA's specific troubleshooting methodology in order, not just knowing facts.

How long should I study for Core 1?

It depends on your background, but plan on several weeks of dedicated study covering all five domains, with extra time set aside for PBQ practice before your exam date.

Do I need Core 1 before Core 2?

No — CompTIA doesn't require a specific order. Most people take Core 1 first since its hardware and networking fundamentals give useful context for Core 2, but you can take either exam first as long as you eventually pass both.

CompTIA A+ Core 1 (220-1201) Study Guide

Updated August 2026

Core 1 (220-1201) is the hardware-and-infrastructure half of CompTIA A+ — mobile devices, networking, physical hardware, virtualization, and troubleshooting. This guide walks the five domains in exam order, tells you what each one actually tests, and closes with a study sequence you can follow start to finish.

1.0 Mobile Devices (13%)

The smallest domain, but a common source of easy points if you drill it early. It covers laptop hardware — replacing RAM, storage, keyboards, and batteries — plus display technologies, wireless expansion, and mobile accessories and connectivity.

Expect direct identification questions: a photo of a SODIMM slot next to a battery connector, or a digitizer ribbon cable next to a display data cable, and you have to name the part or the tool. CompTIA also tests laptop repair order — which components are reachable from a bottom access panel (RAM, storage, battery, sometimes the Wi-Fi card) versus which require a full teardown (keyboard, palm rest, display assembly, motherboard).

Laptop hardware: what's field-replaceable vs. what requires disassembly, screen types, digitizers, webcams, and internal antenna leads.
Display technologies: OLED vs. IPS vs. TN, native resolution, refresh rate, and touchscreen digitizer basics — including why a cracked digitizer doesn't always mean a cracked panel.
Connector types: USB-C, Lightning, Thunderbolt, and the mobile-specific ports (and proprietary charging connectors) you won't see as often on desktops.
Wireless expansion: swapping a Wi-Fi/Bluetooth combo M.2 card, and recognizing internal antenna cable colors and routing.
Mobile accessories: docking stations, port replicators, trackpads, styluses, and Bluetooth/NFC pairing basics.
Rugged and durability specs: MIL-STD ratings and IP (ingress protection) codes — these show up as scenario questions about choosing the right device for field or outdoor work.

2.0 Networking (23%)

The second-biggest domain and the one people most often underestimate. It covers ports and protocols, wireless standards, cabling and network hardware, SOHO network configuration, and IP addressing services like DHCP and DNS.

This domain rewards rote memorization more than any other on Core 1 — port numbers and the 802.11 table don't have shortcuts, so drill them with flashcards until recall is instant, not just recognizable on a multiple-choice list.

Ports and protocols cold: memorize the common TCP/UDP port numbers (20/21 FTP, 22 SSH, 23 Telnet, 25 SMTP, 53 DNS, 80 HTTP, 443 HTTPS, 3389 RDP, and the rest) — this is tested directly and constantly.
The 802.11 table: know 802.11a/b/g/n/ac/ax by frequency band, max theoretical speed, and range — a favorite drag-and-drop and PBQ target.
Cabling standards: T568A vs. T568B termination, straight-through vs. crossover cable use cases, and cable categories (Cat 5e/6/6a) by rated speed.
Network hardware: what a switch, router, access point, and patch panel each actually do, and where each one sits in a basic SOHO topology.
SOHO router configuration: DHCP scopes, port forwarding, firewall rules, and basic wireless security settings (WPA2/WPA3).
DHCP and DNS: how a client gets an address (discover/offer/request/ack) and how name resolution actually works, including common troubleshooting symptoms like APIPA addresses (169.254.x.x) pointing to a failed DHCP lease.

3.0 Hardware (25%)

The biggest single-topic domain — physical components. Cables, RAM, storage, motherboards, CPUs, power supplies, and printers all live here, and Core 1 expects you to identify parts by sight and spec, not just name them.

Treat this domain like a parts catalog: for every component, know its job, its common connector, and the one spec that determines compatibility (socket type for a CPU, form factor for a motherboard, wattage headroom for a PSU). PBQs in this domain often show a photo and ask you to pick the matching cable or slot.

RAM types: DDR4 vs. DDR5, SODIMM vs. DIMM, single/dual/quad channel — know which goes in a laptop vs. desktop, and why mismatched RAM speeds cause instability.
Storage and RAID: SATA vs. NVMe vs. M.2, and RAID 0/1/5/10 — RAID 0 stripes for speed with no redundancy, RAID 1 mirrors for redundancy, RAID 5 uses parity across the array for a balance of the two, and RAID 10 combines mirroring and striping (not parity) for both speed and redundancy — know what each protects against and what it costs you in usable capacity.
Motherboards and CPUs: form factors (ATX, microATX, ITX), chipset basics, CPU socket types, single vs. multi-core, and cooling methods (air vs. liquid).
Power supplies: wattage sizing, 80 Plus efficiency ratings, and connector types (24-pin, EPS, PCIe power) — know which connector powers which component.
Cables and connectors: video (HDMI, DisplayPort, DVI, VGA) and peripheral (USB-A/B/C by version — 2.0, 3.0/3.1/3.2 — and their max throughput).
Printer maintenance by type: laser (toner, fuser, drum, replace the maintenance kit), inkjet (cartridges, calibration, print head cleaning), thermal (heating element, feed assembly), and impact — each has a distinct maintenance procedure and CompTIA tests the differences directly.

4.0 Virtualization and Cloud Computing (11%)

The smallest Core 1 domain — treat it as quick wins, since the vocabulary is limited and mostly definitional. It covers cloud service and deployment models, the characteristics that make cloud computing "cloud," and client-side virtualization on your own machine.

Don't skip this one just because it's small — an 11% domain you've fully mastered is worth more than an extra hour spent re-reviewing a domain you already know cold.

Cloud service models: IaaS vs. PaaS vs. SaaS — know a real example of each and who manages what layer (hardware, OS, application).
Cloud deployment models: public vs. private vs. hybrid vs. community.
Cloud characteristics: on-demand self-service, rapid elasticity, resource pooling, and measured service — the vocabulary CompTIA likes to test by definition, not just by name.
Client-side virtualization: what a hypervisor does (Type 1 vs. Type 2), why you'd run a VM locally (testing, isolation, legacy software), and basic resource requirements — RAM allocation, storage, and CPU virtualization support (VT-x/AMD-V) enabled in firmware.
Shared vs. dedicated resources and snapshots: how a VM snapshot lets you roll back a bad change, and the tradeoff of over-committing host resources across multiple guest VMs.

5.0 Hardware and Network Troubleshooting (28%)

The biggest domain on the exam, and the one that determines whether you pass. It's built around CompTIA's six-step troubleshooting methodology: 1) identify the problem, 2) establish a theory of probable cause, 3) test the theory to determine the cause, 4) establish a plan of action to resolve the problem and implement the solution, 5) verify full system functionality and, if applicable, implement preventive measures, and 6) document findings, actions, and outcomes. Plus symptom-to-cause reasoning across hardware, printers, and networks.

The methodology isn't just theory — CompTIA writes entire PBQs around it, presenting a scenario and asking you to pick the next correct step given where the tech already is in the process. Skipping ahead to a plausible-sounding fix, even a correct one, scores wrong if it's out of order.

The methodology order matters. PBQs and scenario questions penalize skipping steps, like jumping straight to a fix before you've confirmed the theory, or implementing a plan without first establishing one.
Symptom-to-cause tables: POST beep codes, no-boot symptoms, overheating, distended capacitors, a clicking hard drive (often imminent mechanical failure), intermittent connectivity, and print-quality defects (streaks, ghosting, faded output) — practice mapping symptom to most likely cause, not every possible cause.
Network troubleshooting: limited connectivity, IP conflicts, slow performance, and using tools like ping, ipconfig/ifconfig, tracert, and a cable tester or toner probe to physically trace a bad run — to isolate where a problem sits.
Hardware troubleshooting tools: a multimeter for power issues, loopback plugs for port testing, and POST diagnostic cards for boot failures that don't reach video.

How to study this

Start from the official objectives for 220-1201 — everything on the exam maps to a line item there.
Work one domain at a time, in order, and don't move on until you can explain it without notes.
Start PBQ practice early, not at the end — practice PBQs free at examwizardz.app/pbq-practice, since they're weighted heavily and reward familiarity with the interface, not just the content.
Take a free practice test at examwizardz.app/practice-test/comptia-a-plus-core-1 once you've covered all five domains, then re-drill whatever it exposes.

Core 1 passes at 675 out of 900. Troubleshooting (28%) and Hardware (25%) alone make up more than half the exam — prioritize accordingly.