The correct command to grant temporary elevated privileges in Linux is sudo, which stands for "superuser do." The sudo command allows authorized users to execute a command as the superuser or another user, providing a level of access control.

The top command provides a bird's-eye view of the system's current resource usage, including CPU, RAM, and swap. It offers real-time monitoring of processes and their resource consumption.

Docker is a technology that allows you to package applications and their dependencies into containers. It's an excellent choice for deploying microservices, as it ensures that each service is encapsulated with its dependencies and configurations, making it highly reproducible and scalable.

In Bash scripting, the test command is used to test for file types and compare values. It is often used with conditional statements like if and elif to perform tests on files, strings, and other expressions. The test command is also equivalent to [ ] in Bash.

The primary purpose of the /home directory in Linux is to store user home directories. Each user on a Linux system typically has a subdirectory within /home where their personal files and settings are stored.

During the boot process, the BIOS/UEFI (Basic Input/Output System/Unified Extensible Firmware Interface) is responsible for loading the kernel into memory. The BIOS/UEFI is the firmware that initializes the hardware and starts the boot process. It locates the bootloader, which, in turn, loads the kernel into memory to start the operating system.

To lockdown a specific application on an Ubuntu server by restricting it to a limited set of resources, you would primarily utilize "AppArmor." AppArmor is a Mandatory Access Control (MAC) framework that allows you to define and enforce application-specific security policies, confining applications to their designated resources and actions.

The default field separator for operations like splitting strings is determined by the IFS (Internal Field Separator) built-in variable. The IFS variable defines how the shell separates words when it parses strings, making it a crucial component for tasks like parsing CSV files or text processing in scripts.

In a shell script, you would use the $_ special variable to refer to the last argument passed. This variable holds the last argument to the last command that was executed.

In a Debian-based system, such as Ubuntu, you would likely use the 'apt-get' command to install packages. The 'apt-get' command is used for package management and is specifically designed for Debian-based distributions.