# IC3/Network Fundamentals

A computer network (or data network) is a telecommunications network that allows computers to exchange data.
This lesson introduces network fundamentals and helps learners prepare for the IC$^3$ Living Online certification exam.

## Objectives and Skills

Objectives and skills for the network fundamentals portion of IC$^3$ certification include:
Objectives
* Identify network fundamentals and the benefits and risks of network computing
Skills
* Internet Connection: Speed, wired, wireless, security, network types and features, capabilities, publicly switched networks, DNS, addressing, LAN vs. WAN, VPN
* Network troubleshooting: Solve simple scenarios, identify common problems, define IP addressing

## Readings

* Wikibooks: Introduction to Computer Information Systems/Computer Networks
* Wikipedia: Computer network
* Wikipedia: Domain Name System
* Wikipedia: IP address
* Wikipedia: Internet Access

## Multimedia

* YouTube: Introduction to Computer Networks Part 1 - Easy to understand basics
* YouTube: Introduction to Computer Networks Part 2 - Easy to understand basics
* YouTube: Introduction to Computer Networks Part 3 - Easy to understand basics
* YouTube: Introduction to Networking
* YouTube: DNS Explained

## Activities

* Complete the tutorial Connecting to the Internet. Compare costs and speed of dial-up networking, cable, DSL, wireless, and satellite Internet providers in your area.
* Review Connect to a VPN in Windows 10. Configure your computer to connect to a virtual private network.

## Lesson Summary

* Internet connection is the ability of individuals and organizations to connect to the Internet using computer terminals, computers, mobile devices; and to access services such as email and the World Wide Web.
* There are many different kinds of internet connections. A few of these connections consist of wireless, broadband, and dial-up. Wireless is a router or a network that connects to a hot spot. A broadband is connected directly to a broadband modern, and one needs a user name and password to connect. A dial-up is used remotely via a telephone line.
* Network Fundamentals consist of different types of networking and includes networking equipment, Wi-fi, internet service, internet protocols, and internet routing, switching and bridging.

## Key Terms
### Access point, wireless (WAP)

    A networking hardware device that allows a Wi-Fi compliant device to connect to a wired network.

### application service provider (ASP)

    A business providing computer-based services to customers over a network; such as access to a particular software application (such as customer relationship management) using a standard protocol (such as HTTP).

### dial-up internet access

    A form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telephone line. The user's computer or router uses an attached modem to encode and decode information into and from audio frequency signals, respectively.

### Domain Name System (DNS)

    A hierarchical decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates more readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols. By providing a worldwide, distributed directory service, the Domain Name System is an essential component of the functionality of the Internet, that has been in use since 1985.

### Digital subscriber line (DSL)

    A family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology, for Internet access.

### Domain Name System (DNS)

    A hierarchical decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities.

### encryption

    The translation of data into a secret code and is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it. Unencrypted data is called plain text; encrypted data is referred to as cipher text.

### host (network)

    A computer or other device connected to a computer network. A network host may offer information resources, services, and applications to users or other nodes on the network. A network host is a network node that is assigned a network layer host address.

### Internet

    The global system of interconnected computer networks that use the Internet protocol suite to link devices worldwide. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web, electronic mail, telephony, and file sharing.

### Intranet

    A private network accessible only to an organization's staff. Generally a wide range of information and services from the organization's internal IT systems are available that would not be available to the public from the Internet.

### Internet Protocol address (IP address)

    An identifier assigned to each computer and other device (e.g., printer, router, mobile device, etc.) connected to a TCP/IP network$^{[1]}$ that is used to locate and identify the node in communications with other nodes on the network. Each ISP or private network administrator assigns an IP address to each device connected to its network. Such assignments may be on a static (fixed or permanent) or dynamic basis, depending on its software and practices.

### Internet Service Provider (ISP)

    A company that provides Internet services, including personal and business access to the Internet.

### Internet privacy

    involves the right or mandate of personal privacy concerning the storing, repurposing, provision to third parties, and displaying of information pertaining to oneself via of the Internet. Internet privacy is a subset of data privacy. Privacy concerns have been articulated from the beginnings of large scale computer sharing.

### LAN (local area network)

    A computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building[1] and has its network equipment and interconnects locally managed.

### modem (modulator-demodulator)

    A network hardware device that modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used with any means of transmitting analog signals, from light emitting diodes to radio. A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data.

### MMORPG (Massively multiplayer online role-playing games)

    A combination of role-playing video games and massively multiplayer online games in which a very large number of players interact with one another within a virtual world. As in all RPGs, the player assumes the role of a character (often in a fantasy world or science-fiction world) and takes control over many of that character's actions. MMORPGs are distinguished from single-player or small multi-player online RPGs by the number of players able to interact together, and by the game's persistent world (usually hosted by the game's publisher), which continues to exist and evolve while the player is offline and away from the game. MMORPGs are played throughout the world.

### network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface)

    A computer hardware component that connects a computer to a computer network.

### network operating system (NOS)

    A specialized operating system for a network device such as a router, switch or firewall.

### networking

    The practice of linking two or more computing devices together for the purpose of sharing data.

### packet-switching

    A digital networking communications method that groups all transmitted data into suitably sized blocks, called packets, which are transmitted via a medium that may be shared by multiple simultaneous communication sessions. Packet switching increases network efficiency and robustness, and enables technological convergence of many applications operating on the same network. Packets are composed of a header and payload. Information in the header is used by networking hardware to direct the packet to its destination where the payload is extracted and used by application software.

### Rootkit

    A collection of computer software, typically malicious, designed to enable access to a computer or areas of its software that would not otherwise be allowed (for example, to an unauthorized user) and often masks its existence or the existence of other software. The term "rootkit" has negative connotations through its association with malware.

### TCP/IP (Transmission Control Protocol/Internet Protocol)

    The basic communication language or protocol of the Internet. It can also be used as a communications protocol in a private network (either an intranet or an extranet).

### VPN (virtual private network)

    Extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.

### W3C (World Wide Web Consortium)

    The main international standards organization for the World Wide Web (abbreviated WWW or W3). Founded and currently led by Tim Berners-Lee, the consortium is made up of member organizations which maintain full-time staff for the purpose of working together in the development of standards for the World Wide Web. The W3C also engages in education and outreach, develops software and serves as an open forum for discussion about the Web.

### WAN (wide area network)

    A network that not only covers a larger geographic distance, but also generally involves leased telecommunication circuits or Internet links.

### WLAN (wireless local area network)

    A wireless computer network that links two or more devices using a wireless distribution method (often spread-spectrum or OFDM radio) within a limited area such as a home, school, computer laboratory, or office building. This gives users the ability to move around within a local coverage area and yet still be connected to the network. A WLAN can also provide a connection to the wider Internet. Most modern WLANs are based on IEEE 802.11 standards and are marketed under the Wi-Fi brand name.

### wireless broadband

    Used to provide both fixed and mobile Internet access.

### workgroup

    A network environment in which each computer is responsible for its own security, rather than relying on centralized authentication.

## See Also

* Introduction to Computers
* Introduction to Networking
* Computer Networks

## Additional Resources

* Windows IT Pro: Network Troubleshooting Basics
* Cray: Network Troubleshooting
* Microsoft: IP addressing
* Lifewire: Home Networking Fundamentals
* Green Garage Blog: 14 Main Advantages and Disadvantages of Computer Networking
* Geniusvivek: Top 5 Advantages and Disadvantages of Computer Networking