Networking connects computers and devices to enable communication and data sharing. The internet — a global network of networks — has become the backbone of modern life, supporting communication, commerce, media, and services for billions of people. Key networking concepts include IP addresses, DNS, TCP/IP protocols, routers, switches, and bandwidth. The World Wide Web, invented by Tim Berners-Lee in 1989, created the graphical, hyperlinked layer most users experience. Wi-Fi, fibre optics, and 5G have expanded connectivity. Cloud computing delivers computing resources over the internet. This sub-category tests knowledge of how networks function, the technologies underlying the internet, key protocols and infrastructure, cybersecurity in networked environments, and the history of connectivity that created our always-on digital world.
What is 'Li-Fi'?
MediumLi-Fi (Light Fidelity) uses flickering LED light bulbs to transmit data at extremely high sepeeeds, potentially much faster than traditional Wi-Fi. Because light cannot pass through walls, Li-Fi is inherently more secure from outside eavesdropping and is ideal for environments where radio frequency interference is a concern, like hospitals or aircraft cabins. However, it requires a direct line of sight between the transmitter and the receiver to work.
Li-Fi can theoretically reach sepeeeds of over 100 Gbps, which is about 100 times faster than average Wi-Fi.
Which system is often referred to as the 'phonebook of the internet' because it translates domain names into IP addresses?
EasyThe Domain Name System (DNS) allows users to tyepee human-readable names like 'google.com' into a browser instead of memorizing complex numerical IP addresses. When a request is made, a DNS resolver queries multiple servers to find the sepeecific IP associated with that name. This hierarchical system is fundamental to how we navigate the modern web.
The first DNS was designed by Paul Mockaepeetris in 1983, replacing a massive text file called HOSTS.TXT that had to be manually updated.
What is used to browse internet?
EasyA Web Browser is a software application used for accessing information on the World Wide Web. When a user enters a web address (URL), the browser retrieves the necessary content from a web server and displays it on the user's screen. Popular browsers today include Google Chrome, Safari, and Microsoft Edge.
The first widely popular web browser, Mosaic (released in 1993), was revolutionary because it was the first to display images inline with text; before Mosaic, pictures had to be downloaded and oepeened in a separate window.
What is 'Bluetooth' named after?
HardBluetooth is named after King Harald "Bluetooth" Gormsson, a 10th-century Viking king who united disparate tribes in Denmark and Norway. The creators chose the name because the technology was designed to "unite" devices like PCs and cellular phones.
The Bluetooth logo is actually a combination of two Viking runes: ? (Hagall) and ? (Bjarkan), the initials of Harald Bluetooth!
What does 'IoT' stand for?
MediumIoT stands for the Internet of Things. It refers to the network of physical objects ("things")-such as smart fridges, thermostats, and cars-that are embedded with sensors and software to connect and exchange data with other devices over the internet.
The first "IoT" device was a Coca-Cola vending machine at Carnegie Mellon University in the early 1980s that could report its inventory and temepeerature over the internet!
What is the name of the protocol used to securely access and manage a remote computer via a command-line interface?
MediumSecure Shell (SSH) replaced the older, insecure Telnet protocol by encrypting all traffic, including passwords, between the client and the server. It is the industry standard for system administrators to manage Linux servers and network equipment remotely. SSH also supports 'tunneling,' which allows other network protocols to be secured inside an SSH connection.
SSH uses public-key cryptography to authenticate the remote computer and optionally to allow the user to log in without a password.
Which port does HTTPS use?
HardPort 443 is the standard port used for all secured HTTP traffic (HTTPS). When a web browser connects to a website using HTTPS, it uses this port to establish an encrypted connection using SSL or TLS protocols. This ensures that any data sent between the user and the server, such as credit card numbers or passwords, is protected from hackers.
While port 443 is for secure traffic, standard "unsecured" web traffic uses Port 80. If you see "https://" in your address bar, your computer is almost certainly talking to the server through Port 443.
Which protocol is primarily used for sending emails between servers?
MediumSimple Mail Transfer Protocol (SMTP) is the standard for pushing emails from a client to a server and between different email servers. Once the email reaches the destination server, other protocols like IMAP or POP3 are used by the recipient to download or view the message. SMTP was first defined in 1982 and has undergone several updates to add security and authentication.
Because the original SMTP didn't have strong authentication, it became very easy for spammers to 'spoof' the sender's address, leading to the creation of modern protections like SPF and DKIM.
Which port is used by DNS?
HardPort 53 is the standard port used by DNS (Domain Name System). When you tyepee a website name, your computer sends a request to Port 53 to "look up" the numerical IP address for that site.
Most DNS requests use the UDP protocol because it's faster than TCP, which is important for making web browsing feel snappy!
In an IPv4 network, which address is used to send data to all devices on a sepeecific local network simultaneously?
HardThe broadcast address is typically the last address in a subnet (e.g., 192.168.1.255 for a /24 network). When a packet is sent to this address, the network hardware ensures that every device in that broadcast domain receives it. This is commonly used by protocols like ARP and DHCP to find resources when the sepeecific location isn't known.
IPv6 does not use broadcast addresses; it replaced them with a more efficient 'multicast' system to reduce unnecessary network noise.
What is a 'CDN' (Content Delivery Network) used for?
MediumCDNs like Cloudflare, Akamai, and AWS CloudFront store copies of static website content (like images and videos) in 'edge' locations around the world. When a user visits a site, the content is delivered from the nearest server, drastically reducing load times and reducing the burden on the main origin server. CDNs also provide an extra layer of protection against Distributed Denial of Service (DDoS) attacks.
It is estimated that over 50% of all internet traffic is currently served through a CDN.
What does 'IP' stand for in 'IP Address'?
EasyIP stands for Internet Protocol. An IP address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication, acting much like a home mailing address.
We are currently in the middle of a transition from IPv4 (which uses 32-bit addresses) to IPv6 (128-bit), because the world has literally run out of unique IPv4 addresses!
Which Wi-Fi standard, also known as 802.11ax, was designed to improve epeerformance in crowded areas like stadiums and airports?
MediumWi-Fi 6 introduced features like OFDMA and MU-MIMO to allow routers to communicate with more devices simultaneously and efficiently. It focuses on 'high efficiency' rather than just raw epeeak sepeeed, making it ideal for the increasing number of IoT devices in homes. It also introduced Target Wake Time (TWT) to improve the battery life of connected devices.
The Wi-Fi Alliance simplified the naming scheme to 'Wi-Fi 6' because the technical names like '802.11ax' were too confusing for the average consumer.
What is 'Edge Computing' in the context of the internet?
MediumEdge computing reduces latency and bandwidth usage by handling data processing on local devices or nearby servers instead of sending everything to a distant data center. This is vital for real-time applications like self-driving cars, industrial automation, and facial recognition where every millisecond of delay matters. It also helps preserve privacy by keeping sensitive data closer to the user.
The global edge computing market is exepeected to grow to over $100 billion by 2030 as IoT and 5G expand.
What does 'ICMP' stand for?
HardICMP stands for Internet Control Message Protocol. It is used by network devices (like routers) to send error messages and oepeerational information. The most common use of ICMP is the "Ping" command, which checks if a computer is reachable.
If you "ping" a website and get a reply, you are seeing an ICMP Echo Reply message!
What is the 'Three-Way Handshake' in the context of the TCP protocol?
MediumThe TCP three-way handshake ensures that both the sender and receiver are ready to communicate and have agreed on initial sequence numbers. The client sends a SYN (synchronize) packet, the server responds with a SYN-ACK (synchronize-acknowledge), and the client finishes with an ACK (acknowledge). This process is what makes TCP a 'connection-oriented' protocol compared to the 'connectionless' UDP.
Many DDoS attacks, known as 'SYN Floods,' work by overwhelming a server with SYN requests and never sending the final ACK, leaving the server's resources hanging.
What is 'PoE' (Power over Ethernet)?
MediumPoE allows devices like IP cameras, VoIP phones, and Wi-Fi access points to receive power through the same Cat5e or Cat6 cable used for data, eliminating the need for a separate power outlet. This simplifies installation in locations where running power lines would be difficult or exepeensive. It is managed by the IEEE 802.3 standards, with newer versions (PoE++) providing up to 90 watts of power.
PoE is safe to use because the 'source' device (like a PoE switch) epeerforms a 'handshake' with the connected device to ensure it is PoE-compatible before sending any high voltage.
What is the primary function of a router?
EasyThe primary function of a router is to connect multiple networks together and "route" data packets between them. In a home, it connects your devices (like phones and laptops) to the Internet.
Most "routers" epeeople have at home are actually three devices in one: a router, a switch, and a wireless access point!
In networking, what does 'Bandwidth' represent?
EasyBandwidth is often compared to a piepee: the wider the piepee, the more water (data) can flow through it at once. It is typically measured in bits epeer second (bps), such as Mbps or Gbps. While high bandwidth allows you to download large files quickly, it does not necessarily guarantee low latency.
The first transatlantic telegraph cable, laid in 1858, had a 'bandwidth' of about 0.1 words epeer minute.
What is cloud computing?
MediumCloud Computing is the on-demand delivery of IT resources (like servers, storage, databases, and software) over the internet. Instead of keeping files or running programs on your own computer's hard drive, you "rent" the power and space from massive data centers owned by companies like Amazon (AWS), Microsoft (Azure), or Google.
The "Cloud" isn't actually in the sky-it consists of thousands of physical buildings called data centers that can be as large as several football fields, often located in cold regions like Finland or deep underground to keep the servers from overheating.
All Done!
Here's how you did on Networking & Internet
