Home Networks and Internet Connectivity

• Computer networks enable communication by connecting two or more computers.

Protocols

• Protocols are rules that dictate how messages are successfully transmitted, like the "@" symbol in email addresses or "http://" for web addresses.

Network Cables

• Network cables connect devices using plastic plugs and copper wires, allowing data to flow in both directions.

Hubs

• Hubs connect multiple computers together via ports for cable connections.

Routers

• Routers connect networks across large areas, forwarding messages between them and acting as gateways.
• A common use of routers is connecting a home network to the internet via an ISP.

Servers

• Servers are powerful computers that offer services, such as file servers that store various file types accessible to all devices on a network.

Wired Connections

• Wired networks transmit data through ethernet cables.

Wireless Connections

• Wireless networks transmit data through the air using radio waves, including technologies like Bluetooth, WiFi, 4G, and 5G.

Bandwidth

• Bandwidth measures the amount of data transferred from one point to another in a specific timeframe.
• Higher bandwidth means more data can be moved per second, but it does not affect speed.

Bits per Second

• Bandwidth is measured in bits per second (bps), with a bit being the smallest data unit.
• Due to high data transfer rates, bandwidth is often measured in Megabits per second (Mbps), where 1 Mb equals 1 million bits.

Internet Service Provider

• ISPs provide internet access to individuals, households, and companies.

Buffering

• Buffering occurs when data arrives slower than it's being processed, indicating a need for more bandwidth.
• Buffering is exemplified when a video pauses and requires loading time.

Internet

• The internet is a global network of interconnected computers and the physical hardware that supports them.
• Any device connected to the internet is part of this global network.

Ocean Internet Cabling

• Subsea cables transmit 99% of internet data across continents.

Packets

• Networks transmit messages in packets, which are small data units.
• Large messages are divided into multiple packets, each containing a message fragment, a sender address, and a receiver address.
• IP addresses are unique addresses for each packet.

IP Address

• An IP (Internet Protocol) address uniquely identifies devices on the internet.
• An IP address consists of four number groups (0-255) separated by periods.
• An example IP address is 192.168.5.43.

Internet Protocol

• IP facilitates packet routing.
• Each device uses an IP address for unique identification.

Transmission Control Protocol

• TCP divides messages into packets for internet transmission.
• TCP reassembles packets in the correct order at the receiving end.

Digital Footprint

• A digital footprint includes all online information about an individual, such as website visits, emails, and data submitted to online services.

Metadata

• Metadata is "data about data," which is additional information exchanged with content by apps and devices, often without user awareness.

Privacy Policy

• A privacy policy is a simple statement explaining how an organization handles personal information.

Packet Header

• A packet header includes the sender IP address, receiver IP address, total number of packets, and the sequence number of the specific packet.
• Computers use the sequence number in the packet header to reassemble data in the correct order once all packets are received.

Packet Payload

• Packet payload contains the actual message being sent.

Privacy

• Internet privacy is the ability to control who can see or use your online information.

Keylogging

• Keylogging software records every keystroke to steal passwords and confidential data.

Malware

• Malware is software designed to damage systems or gain control over their operation.

Phishing

• Phishing tricks users into revealing personal information, which can then be used to access sensitive online accounts and resources.

Encryption

• Encryption encodes messages to keep them secret and readable only by authorized parties.

Decryption

• Decryption reverses encryption, turning secret messages back into readable text.

Cipher

• A cipher is a technique or algorithm used for encryption.

Caesar Cipher

• The Caesar cipher shifts letters in the alphabet by a fixed number of positions.

Cracking Encryption

• Cracking encryption involves attempting to decode a secret message without full knowledge of the cipher used.

Random Substitution Cipher

• A random substitution cipher matches each alphabet letter with a different, randomly chosen letter.

Single Factor Authentication

• Single-factor authentication requires only one element of secrecy.

Two Factor Authentication

• Two-factor authentication requires two elements of secrecy.

Multifactor Authentication

• Multifactor authentication requires three or more elements of secrecy.

Computer Virus

• A computer virus is a type of malware that spreads between computers, damaging data and software.

Explore the function of routers in connecting home networks to the internet and the relationship between bandwidth and data transfer. Understand buffering issues in video streaming and essential components for successful network communication. Learn about optimizing network performance in a school computer lab and the distinction between the Internet and local networks.