Explanation
DDR3 is the most commonly used RAM type in modern desktop computers. It is faster and more energy efficient than its predecessors, and offers larger capacity modules. References: CompTIA A+ Certification Exam Guide, Ninth Edition, Chapter 5

Explanation
http://www.221021.com/Hardware/input-output-devices/32310.html
1. Identify the problem.
Gather information from the user, identify user changes, and, if applicable, perform backups before making changes.
Inquire regarding environmental or infrastructure changes.
2. Establish a theory of probable cause (question the obvious).
If necessary, conduct external or internal research based on symptoms.
3. Test the theory to determine the cause.
Once the theory is confirmed, determine the next steps to resolve the problem.
If the theory is not confirmed, re-establish a new theory or escalate.
4. Establish a plan of action to resolve the problem and implement the solution.
Refer to the vendor's instructions for guidance.
5. Verify full system functionality and, if applicable, implement preventive measures.
6. Document the findings, actions, and outcomes.

Explanation
UEFI stands for Unified Extensible Firmware Interface, and it is a type of firmware that controls the boot process of a computer. UEFI settings allow the technician to configure various aspects of the boot process, such as the boot order, the boot mode, and the security options. If the technician replaces a laptop hard drive with an M.2 SSD, they may need to adjust the UEFI settings to enable the system to detect and boot from the new drive.

Explanation
M.2 is a form factor for solid-state drives (SSDs) that enables direct attachment to the motherboard without the need for cables. Thunderbolt is a high-speed interface that supports data transfer, video output, and charging.
eSATA is an external interface for connecting SATA devices. SCSI is an older interface standard for connecting hard drives, printers, and other peripherals.
Installing a hard drive directly on the motherboard without using cables is usually done with an M.2 slot.
References: CompTIA A+ Certification Exam Guide, Ninth Edition, Chapter 5

Explanation
A redundant power supply is a device that provides two or more power supplies connected in parallel so that when one fails, the other one will take over to ensure continuous power. This is ideal for critical warehouse machines that require a reliable power source and are at risk of downtime in the event of a power failure.
Installing a redundant power supply will help to reduce the chances of an unexpected power outage and keep the machine running.