LPI Linux Essentials (010-160) - Linux Foundation

The main difference between hard disk drives (HDDs) and solid state drives (SSDs) is the way they store and access data. HDDs use a spinning disk (platter) and a moving head to read and write data,<br />
while SSDs use flash memory chips that have no moving parts. This makes SSDs faster, quieter, and<br />
more durable than HDDs, but also more expensive and less spacious. HDDs and SSDs are both I/O devices that can be used to boot the system and store data, but they have different advantages and disadvantages depending on the use case. Reference: Difference between Hard Disk Drive (HDD) and Solid State Drive (SSD) Hard Disk Drive (HDD) vs. Solid State Drive (SSD): What’s the Difference?<br />
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How to Check Whether Your Disk Is an SSD or HDD on Linux

Reverse DNS lookups query DNS servers for a PTR (pointer) record; if the server does not have a PTR record, it cannot resolve a reverse lookup. PTR records store IP addresses with their segments reversed, and they append “.in-addr.arpa” to that. For example, if a domain has an IP address of 192.0.2.1, the PTR record will store the domain’s information under 1.2.0.192.in-addr.arpa. In IPv6, the latest version of the Internet Protocol, PTR records are stored within the “.ip6.arpa” domain instead of ".in-addr.arpa."1 Therefore, the name of the IP address 198.51.100.165 is stored in the PTR record for 165.100.51.198.in-addr.arpa. Reference: 1: Reverse DNS lookup - Wikipedia 1

A bus is a communication system that transfers data between components inside a computer or between computers. There are different types of buses that serve different purposes. The RAM bus connects the CPU with the main memory, the NUMA bus connects multiple processors in a multiprocessor system, the CPU bus connects the CPU with other components on the motherboard, and the Auto bus is a fictional bus that can transform into a robot. The SATA bus is the correct answer because it is a type of bus that can connect hard disk drives with the motherboard. SATA stands for Serial Advanced Technology Attachment and it is a standard interface for connecting storage devices such as hard disk drives, solid state drives, and optical drives. SATA offers faster data transfer rates, lower power consumption, and improved cable management compared to older interfaces such as<br />
<br />
IDE and SCSI. Reference: : [Bus (computing)] : [Transformers: Robots in Disguise (2015 TV series)] : [Serial ATA]3) : [SATA vs. IDE: What’s the Difference?]

CentOS is a Linux distribution that is based on the source code of Red Hat Enterprise Linux (RHEL). It is a free and open-source community-supported OS that provides an enterprise-level computing platform. CentOS is fully compatible with RHEL and can run the same applications and packages. Therefore, CentOS allows the team members to apply as much of their Red Hat Enterprise Linux knowledge as possible for their hobby project. Reference: Linux Essentials Version 1.6 Objectives1, Topic 1.1: Linux Evolution and Popular Operating Systems, Subtopic: Linux Distributions Linux Essentials Version 1.6 Exam Preparation Guide2, Section 1.1: Linux Evolution and Popular Operating Systems, Page 7 CentOS Website3, About CentOS Linux Red Hat Enterprise Linux derivatives - Wikipedia4

The top command is a Linux command that shows the running processes on the system. It provides a dynamic real-time view of the system performance and resource usage. The top command can display various information about the processes, such as their process ID, user, priority, state, CPU and memory usage, command name, and more. The top command can also sort the processes by different criteria, such as CPU or RAM consumption, by using the interactive commands. The top command is useful for monitoring the system load and identifying the processes that are consuming the most resources. Reference: Linux Essentials Topic 104: The Linux Operating System, section 104.3: Basic features and commands of the Linux standard shells. Linux Essentials Topic 106: Security and File Permissions, section 106.4: Monitor and manage Linux processes.