Computer Science
Internet
A global network connecting millions of computers, making it possible to exchange information.
fiber-optic cable
Cable that uses light guided through thin glass tubes, instead of electrical signals, to transmit data. It is very fast but also expensive.
LAN
Connects two or more devices within a limited geographic region
Types of Computer Networks
LAN, CAN, MAN, WAN, P2P, INTERNET
Pros and cons of coaxial cable
Mid bandwidth, less susceptible to interference Expensive and inflexible
Cloud Computing
dropbox, gaming advantages-cheap, data is backed up, aces abywhere,
Router
A router is a device that connects two or more packet-switched networks or subnetworks. It serves two primary functions: managing traffic between these networks by forwarding data packets to their intended IP addresses, and allowing multiple devices to use the same Internet connection.
protocol
A set of rules governing the exchange or transmission of data between devices.
wireless controller
A wireless LAN controller is a network device used to monitor and manage wireless access points in an organization. WLCs are connected to routers and allow devices from across the organization to connect to the router via access points
Bandwidth
Amount of Infor that can be transferred across the network at a time.
Internet 2
As a result, Internet2 has been developed by many U.S. universities collaborating with industry and government. Internet2 develops and deploys advanced network applications such as remote medical diagnosis, digital libraries, distance education, online simulation, and virtual laboratories. It is designed to be fast, always on, everywhere, natural, intelligent, easy, and trusted. Note that Internet2 is not a separate physical network from the Internet.
Switch
Switch is a network device that is used to segment the networks into different subnetworks called subnets or LAN segments.
On premise accounting
Traditionally, organizations have used on-premise computing. That is, they own their IT infrastructure (their software, hardware, networks, and data management) and maintain it in their data centers.
coaxial cable
insulated copper wire; used to carry high-speed data traffic and television signals
Transmission Control Protocol (TCP)
provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. TCP is tightly linked with IP and usually seen as TCP/IP in writing.
computer networking
the sharing of data or services between computers using wireless or cable transmission media
wireless acess point
enables devices to connect to a wireless network to communicate with each other
M A C adresss
A media access control address is a unique identifier assigned to a network interface controller for use as a network address in communications within a network segment.is a 12-digit hexadecimal number assigned to each device connected to the network. Primarily specified as a unique identifier during device manufacturing, the MAC address is often found on a device's network interface card (NIC).
twisted-pair cable
Cables made of copper wires that are twisted around each other and are surrounded by a plastic jacket (such as traditional home phone wire).
PROS & CONS TWISTED PAIR
Cheap, Widely avaible, easy to work with subject to interference, slow and easily hacked,
Cloud computing
Cloud Computing Encompasses the Characteristics of Utility Computing. In utility computing, a service provider makes computing resources and infrastructure management available to a customer as needed. The provider then charges the customer for its specific usage rather than a flat rate. Utility computing enables companies to efficiently meet fluctuating demands for computing power by lowering the costs of owning the hardware infrastructure. Cloud Computing Uses Broad Network Access. The cloud provider's computing resources are available over a network, accessed with a Web browser, and they are configured so that they can be used with any computing device. Cloud Computing Pools Computing Resources. The provider's computing resources are available to serve multiple customers. These resources are dynamically assigned and reassigned according to customer demand. Cloud Computing Often Occurs on Virtualized Servers. Cloud computing providers have placed hundreds or thousands of networked servers inside massive data centers called server farms (see Figure TG 3.1). Recall that a server is a computer that supports networks, thus enabling users to share files, software, and other network devices. Server farms require massive amounts of electrical power, air-conditioning, backup generators, and security. They also need to be located fairly close to fiber-optic communications links (Figure TG 3.2).
Azure at 18 percent, Google at 9 percent, and Alibaba at 5 percent
Google, Microsaft Azure, Amazon,
LAN
Local Area Network set of devices connected together when transfer data using set of communication principles
Simple mail internet protocool
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages.
Wireline media or cable media use physical wires or cables to transmit data and information. Twisted-pair wire and coaxial cables are made of copper, and fiber-optic cable is made of glass. The alternative is communication over broadcast media or wireless media. The key to mobile communications in today's rapidly moving society is data transmissions over electromagnetic media—the "airwaves."
Twisted-pair wire Inexpensive Widely available Easy to work with Slow (low bandwidth) Subject to interference Easily tapped (low security) Coaxial cable Higher bandwidth than twisted-pair Less susceptible to electromagnetic interference Relatively expensive and inflexible Easily tapped (low to medium security) Somewhat difficult to work with Fiber-optic cable Very high bandwidth Relatively inexpensive Difficult to tap (good security) Difficult to work with (difficult to splice) 3 2 3 3 3 1
