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 asks you to reason from symptoms to the most likely cause rather than recall 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

By Jonathon Eades, IT instructor · Updated October 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 second-smallest domain, but a common source of easy points if you drill it early. It covers laptop hardware — replacing RAM, storage, keyboards, batteries, wireless cards and webcams — plus mobile accessories and connection methods, and mobile network and app support.

Practice naming parts by sight: a photo of a SODIMM slot next to a battery connector, or a Wi-Fi antenna lead next to a webcam cable, and you have to name the part or the tool. Learn the laptop repair order too — 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: battery, keyboard, RAM, HDD/SSD, wireless cards, camera/webcam and microphone, plus Wi-Fi antenna connectors and placement.
Physical privacy and security components: biometrics like fingerprint readers, and near-field scanner features.
Connection methods: USB-C, microUSB, miniUSB and Lightning, plus NFC, Bluetooth and tethering/hotspot.
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.
Mobile network and app support: cellular data (3G/4G/5G), hotspots, SIM/eSIM, Bluetooth pairing, location services, MDM for corporate and BYOD devices, and syncing mail, calendar, contacts and cloud storage.

2.0 Networking (23%)

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

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 of the A+ port list), and whether each one runs over TCP or UDP.
The 802.11 table: know 802.11a/b/g/n/ac/ax/be by frequency band (2.4, 5 and 6 GHz), max theoretical speed, and range, plus channels and channel widths.
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 network configuration: IPv4 and IPv6, private vs. public addresses, static vs. dynamic addressing, subnet mask and gateway, and DHCP scopes, reservations, leases and exclusions. Router security, like port forwarding and WPA3, is Core 2.
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 second-biggest domain — physical components. Displays, 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). Practice picking the matching cable or slot from a photo.

Displays: LCD panel types (IPS, TN, VA), OLED and Mini-LED, touch screens and digitizers, inverters, and attributes like pixel density, refresh rate, resolution and color gamut.
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 0/1/5/6/10 — 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, RAID 6 adds a second parity block to survive two drive failures, 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 rating and energy efficiency (80 Plus ratings), 110–120 VAC vs. 220–240 VAC input, 3.3V/5V/12V output, the 20+4 pin motherboard connector, and redundant vs. modular supplies.
Network cables: T568A vs. T568B termination, straight-through vs. crossover use cases, copper categories by rated speed, shielded vs. unshielded twisted pair, coaxial, plenum-rated jackets, and single-mode vs. multimode fiber.
Cables and connectors: video (HDMI, DisplayPort, DVI, VGA, USB-C), peripheral (USB 2.0 vs. 3.0, Thunderbolt, serial), and drive (SATA, eSATA), with their max throughput, plus the connector types from RJ45 to DB9.
Printer maintenance by type: laser (replace toner, apply a maintenance kit, calibrate, clean), inkjet (clean the printheads, swap cartridges, calibrate, clear paper jams), thermal (replace paper, clean the heating element, remove debris), and impact (replace the ribbon, printhead and paper).

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 virtualization concepts: VMs, hypervisors, VDI and containers.

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: shared vs. dedicated resources, metered utilization (including ingress and egress), elasticity, availability, file synchronization, and multitenancy.
Virtualization concepts: 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.
Desktop virtualization and containers: what virtual desktop infrastructure (VDI) gives a user, and how a container differs from a full VM.

5.0 Hardware and Network Troubleshooting (28%)

The biggest domain on the exam, and it's built on scenarios: a symptom, a few facts, and a question about the most likely cause or the right fix. Work through them the way CompTIA's six-step method describes: identify the problem, establish a theory of probable cause, test the theory, plan and implement the fix, verify full system functionality, and document what you found. The 220-1201 objectives list that troubleshooting methodology as a best practice rather than a tested objective, but the scenarios reward the same habits.

When a question gives you symptoms, work them the way the method does: gather the facts, test the likeliest cause, and confirm the fix, rather than reaching for the first part that could be at fault.

Work in order. Gather facts and test a theory before you fix anything, and confirm the whole system works before you call it done. The habit matters more than reciting the step names.
Symptom-to-cause tables: POST beep codes, no-boot symptoms, overheating, swollen capacitors, a clicking hard drive (often imminent mechanical failure), intermittent connectivity, and print-quality defects (lines down the page, double or echo images, faded prints, speckling) — 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, 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, a loopback plug for port testing, and a cable tester or toner probe for wiring faults.

How to study this

Start from the official objectives for 220-1201 — everything on the exam maps to one of its objectives, though CompTIA says its example lists aren't exhaustive.
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 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. For a quick readiness check across the whole exam, the 60-question test at examwizardz.app/practice-test/comptia-a-plus covers both cores.

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