Examples of buzz words in YouTube videos on security

1. Network Fundamentals

IP Address: An IP (Internet Protocol) address is a unique identifier assigned to each device connected to a network. It enables devices to locate and communicate with one another over a network. There are two types:

• IPv4: Composed of four 8-bit numbers separated by dots (e.g., 192.168.1.1).

• IPv6: A more recent version, using hexadecimal numbers, designed to address the limitations of IPv4.

Netmask: A netmask (or subnet mask) is used to divide an IP address into a network and host portion. It defines the range of IP addresses that are within a particular subnet. For example, in a network with a netmask of 255.255.255.0, the first 24 bits represent the network, and the remaining 8 bits are for host addresses.

Gateway: A gateway is a network device that acts as an entry/exit point to another network. It routes traffic between local devices and external networks, such as the internet. For instance, a home router serves as a gateway between local devices (LAN) and the internet (WAN).

DNS (Domain Name System): DNS is a system that translates human-readable domain names (like www.example.com) into IP addresses that computers can understand. For example, when you type a website address in your browser, DNS resolves the domain name to the corresponding IP address.

Subnet: A subnet is a smaller network within a larger network. By subdividing a network into multiple subnets, organizations can improve performance and security. Each subnet has its own range of IP addresses.

DHCP (Dynamic Host Configuration Protocol): DHCP is a network protocol that automatically assigns IP addresses to devices on a network, ensuring that every device has a unique address and can communicate effectively within the network.

WAN (Wide Area Network): A WAN spans a large geographic area, often connecting multiple LANs. The internet is the largest WAN, connecting millions of networks globally.

LAN (Local Area Network): A LAN is a network that connects devices within a limited geographic area, like a home or office. It is typically used for sharing resources such as printers, files, and internet access.

MAC Address: A Media Access Control (MAC) address is a unique identifier assigned to network interfaces (e.g., a network card) for communication within a network. It is used to identify devices on the data link layer of the OSI model.

NIC (Network Interface Card): A NIC is a hardware component that allows a device to connect to a network. Each NIC has a unique MAC address.

Router: A router is a device that forwards data packets between computer networks. Routers determine the best path for data to travel from source to destination, typically functioning between a local network (LAN) and a broader network like the internet (WAN).

Switch: A switch is a network device that connects devices within a LAN, forwarding data packets between them based on MAC addresses. Unlike a hub, which sends data to all devices, a switch is more efficient as it only sends data to the intended recipient.

Hub: A hub is a basic network device that connects multiple devices in a LAN. It broadcasts incoming data to all devices, making it less efficient compared to a switch.

Bridge: A bridge connects two separate networks and operates at the data link layer. It filters traffic between them based on MAC addresses, improving network efficiency by segmenting traffic.

2. Security and Privacy

Firewall: A firewall is a network security system that monitors and controls incoming and outgoing network traffic. It can be hardware-based or software-based and is used to enforce security policies by blocking unauthorized access while allowing legitimate communication.

Proxy Server: A proxy server acts as an intermediary between a user and the internet. It can be used for various purposes, such as privacy, security, or caching web content to improve performance.

VPN (Virtual Private Network): A VPN extends a private network across a public network, enabling secure communication. It encrypts data to protect privacy and can be used to access geo-restricted content or remotely connect to a network.

iptables: Iptables is a Linux utility used to configure the firewall rules for filtering network traffic. It enables system administrators to specify which traffic should be allowed or blocked.

3. Communication Protocols

TCP/IP (Transmission Control Protocol/Internet Protocol): TCP/IP is the foundational suite of protocols that governs communication on the internet. TCP ensures reliable, ordered data transmission, while IP is responsible for addressing and routing data packets.

HTTP (HyperText Transfer Protocol): HTTP is the protocol used for transferring web pages and resources on the internet. It defines how clients (e.g., web browsers) request and receive data from servers.

HTTPS (HyperText Transfer Protocol Secure): HTTPS is an encrypted version of HTTP. It uses SSL/TLS protocols to ensure secure communication between the client and server, protecting data from eavesdropping.

FTP (File Transfer Protocol): FTP is a protocol used for transferring files between computers over a network. It can be used for uploading and downloading files to and from servers.

SMTP (Simple Mail Transfer Protocol): SMTP is used to send email messages between servers. It is the standard protocol for email transmission across networks.

POP3 (Post Office Protocol version 3): POP3 is an email protocol used to retrieve emails from a mail server. It downloads emails to a local device, removing them from the server by default.

IMAP (Internet Message Access Protocol): IMAP is another email retrieval protocol. Unlike POP3, IMAP allows emails to remain on the server, enabling access from multiple devices.

ICMP (Internet Control Message Protocol): ICMP is used for error handling and diagnostics in network communication. It is the protocol used by the ping and traceroute commands to test network connectivity.

ARP (Address Resolution Protocol): ARP is used to map an IP address to a MAC address within a local network, enabling devices to locate each other.

RARP (Reverse Address Resolution Protocol): RARP is the inverse of ARP, mapping a MAC address to an IP address. It was previously used by diskless workstations to discover their IP address but is now largely obsolete.

ping: The ping command is used to test network connectivity. It sends ICMP Echo Request messages to a target IP address and measures the round-trip time.

traceroute: traceroute is a network diagnostic tool that shows the path data packets take from source to destination, helping to identify where delays or failures occur.

netstat: netstat displays network connections, routing tables, and other network statistics, helping administrators monitor network activity.

nslookup: nslookup is a command-line tool used to query DNS servers to obtain information about domain names and IP addresses.

telnet: telnet is a protocol and command-line tool used to connect to remote servers. It is not secure, as it transmits data (including passwords) in plaintext.

ssh (Secure Shell): SSH is a secure alternative to Telnet, providing encrypted communication for remote server access. It is widely used for system administration tasks.

4. System Administration and User Management

Root User: The root user is the most privileged account in a Unix-like system. It has full control over the system and can perform administrative tasks.

Non-Root Admin User: A non-root admin user has administrative privileges but is not the root user. They typically use tools like sudo to perform administrative tasks.

sudo: sudo allows a permitted user to execute a command as the root user or another user, based on configuration in the /etc/sudoers file.

su (Substitute User): su is a command used to switch users in Unix-like systems. The su command can be used to switch to the root user (i.e., su without arguments).

passwd: passwd is a command used to change the password for a user account in Unix-like systems.

systemctl: systemctl is a command used to manage systemd services on Linux. It can start, stop, restart, and manage system services.

journalctl: journalctl is a command used to view logs generated by systemd services.

/etc/shadow, /etc/passwd, /etc/group: These are critical configuration files for user management in Unix-like systems. /etc/passwd contains user account information, /etc/shadow holds password information, and /etc/group stores group memberships.

/etc/sudoers: The /etc/sudoers file defines which users can execute commands with sudo and under what conditions.

/etc/hosts: This file maps hostnames to IP addresses, enabling local hostname resolution without DNS.

/etc/resolv.conf: /etc/resolv.conf contains DNS configuration, listing nameservers used to resolve domain names.

/etc/network/interfaces: This file is used to configure network interfaces in Debian-based Linux distributions.

/etc/hostname: The /etc/hostname file stores the system's hostname, which is used to identify the machine on a network.

motd (Message of the Day): motd is a file that contains a message displayed to users upon login. It often contains system information or important notifications.

5. Virtualization and Cloud Computing

Docker: Docker is a platform for developing, shipping, and running applications inside lightweight, portable containers.

Kubernetes: Kubernetes is an open-source platform used to automate the deployment, scaling, and management of containerized applications. It works with Docker to manage containers.

Container: A container is a lightweight, portable package that contains everything needed to run an application, including the code, libraries, and dependencies.

Virtualization: Virtualization refers to the creation of virtual versions of hardware platforms, storage devices, or network resources. It enables efficient use of resources by running multiple virtual machines on a single physical machine.

Hypervisor: A hypervisor is a piece of software that creates and manages virtual machines. Examples include VMware, Hyper-V, KVM, and Xen.

Cloud Computing: Cloud computing is the delivery of computing services (servers, storage, databases, etc.) over the internet, allowing for scalable, on-demand access to resources.

IaaS (Infrastructure as a Service): IaaS provides virtualized computing resources over the internet. AWS and Azure are examples of IaaS providers.

PaaS (Platform as a Service): PaaS provides a platform that allows developers to build, deploy, and manage applications without worrying about the underlying hardware or software.

SaaS (Software as a Service): SaaS provides software applications over the internet, typically on a subscription basis. Google Workspace and Microsoft 365 are examples.

AWS, Azure, GCP, IBM Cloud, Oracle Cloud, Alibaba Cloud: These are leading cloud service providers offering IaaS, PaaS, and SaaS solutions.

VMware, Hyper-V, KVM, Xen: These are hypervisor technologies used for virtualization, allowing multiple virtual machines to run on a single physical machine.

OpenStack: OpenStack is an open-source cloud computing platform that allows organizations to build and manage their own private clouds.

Conclusion

Understanding these fundamental networking and system administration terms is essential for anyone working in IT, networking, or system administration. This knowledge forms the backbone of building, managing, and securing modern IT infrastructures. Each of these keywords is interrelated, contributing to the functioning of networks and services that power everything from basic internet browsing to complex cloud-based applications.