Explanation
A load balancer is a network device that distributes network or application traffic across multiple servers to ensure that no single server bears too much of the load. Load balancing helps to improve application availability, increase scalability, and optimize resource utilization.
A bridge is used to connect two different networks, often to divide a larger network into smaller segments. A proxy server is used to forward client requests to other servers, and can also be used to cache frequently requested data. A switch is used to connect multiple devices within a network and to control the flow of network traffic. A firewall is used to secure a network by controlling incoming and outgoing traffic based on defined security rules.

Explanation
A load balancer is a network device that distributes network or application traffic across multiple servers to ensure that no single server bears too much of the load. Load balancing helps to improve application availability, increase scalability, and optimize resource utilization.
A bridge is used to connect two different networks, often to divide a larger network into smaller segments. A proxy server is used to forward client requests to other servers, and can also be used to cache frequently requested data. A switch is used to connect multiple devices within a network and to control the flow of network traffic. A firewall is used to secure a network by controlling incoming and outgoing traffic based on defined security rules.
Reference: CompTIA A+ Core 1 Exam Guide, page 244.

A swollen battery can prevent a laptop from powering on as it disrupts connectivity or damages internal components.

Explanation
The first step in troubleshooting any network issue is to identify the problem and gather information from the user and the device. Reviewing the network settings in the OS can help the technician verify if the laptop is configured correctly to connect to the wireless network, such as the SSID, security type, password, IP address, DNS server, etc. This can also help the technician rule out any software or driver issues that might prevent the laptop from connecting to the network. This is a logical and simple step that can be done before attempting any other actions that might affect the network infrastructure or other devices.
References:
CompTIA A+ 220-1101 - 5.1 - How to Troubleshoot
CompTIA A+ Core 1: Troubleshooting Wired & Wireless Networks
CompTIA A+ Core 1 (220-1101) Certification Study Guide

Explanation
The message stating that one or more disks are in a degraded state is a clear indication of a RAID failure.
RAID stands for Redundant Array of Independent Disks, and it is a technology used to provide fault tolerance and improve performance by combining multiple hard drives into a single logical unit.
The message indicating that the OS is missing is most likely caused by a bootable device not found. This means that the server is unable to boot from the designated boot device, which could be the hard drive, a CD/DVD drive, or a USB flash drive. This could be caused by a faulty boot device, a loose cable, or a misconfiguration in the BIOS or UEFI settings.