Unit 2: The Internet

• Path is a sequence of directly connected computing devices that begins at the sender and ends at the receiver
• Route is the process of finding a path from sender to reciever
• A computer Device is a physical artifact that can run a program. Some examples include computers, tablets, servers, routers, and smart sensors
• Computer System is a group of computing devices and programs working together for a common purpose
• Computer Network is a group of interconnected computing devices capable of sending or receiving data
• Bandwidth is the maximum amount of data that can be sent in a fixed amount of time
• Protocol: an agreed-upon set of rules that specify the behavior of some system
• IP address: The unique number assigned to each device on the internet
• Internet Protocol (IP): a protocol for sending data across the Internet that assigns unique numbers (IP addresses) to each connected device
• Router: A type of computer that forwards data across a network
• Redundancy: The inclusion of extra components so that a system can continue to work even if individual components fail, for example by having more than one path between any two connected device in a network
• Fault Tolerant: Can continue to function even in the event of individual component failures. This is important because elements of complex systems like a computer network fail at an unexpected time, often in groups
• Data stream: Information passed through the internet in packets
• Packet: A chunk of data sent over a network. Larger messages are divided into packets that may arrive at the destination in order, out of order, or not at all
• Packet Metadata: Data added to packets to help route them through the network and reassemble the original message
• Transmission Control Protocol (TCP): A protocol for sending packets that does error-checking to ensure all packets are received and properly ordered
• User datagram Protocol (UDP): A protocol for sending packets quickly with minimal error-checking & no resending of dropped packets
• Scalability : The capacity for the system to change in size and scale to meet demands
• World Wide Web : a system of linked pages, programs, & files
• The Domain Name System (DNS): the system responsible for translating domain names like example.com into IP addresses
• Hypertext Transfer Protocol (HTTP): a protocol for computers to request and share the pages that make up the world wide web on the internet

  The world wide web is different from the internet. The world wide web are files, web pages, and media. The internet is the network we use to access these files. The DNS is an important system in helping the internet scale
• Digital Divide - differing access to computing devices and the internet, based on socioeconomic, geographic, or demographic characteristics.

  • can affect both individual and groups
  • raises ethical concerns of equity, access, and influence globally and locally.