Networks Essays - Local Area Networks, IEEE Standards, Free Essays

Networks Essays - Local Area Networks, IEEE Standards, Free Essays Networks Network, in computer science, techniques, physical connections, and computer programs used to link two or more computers. Network users are able to share files, printers, and other resources; send electronic messages; and run programs on other computers. A network has three layers of components: application software, network software, and network hardware. Application software consists of computer programs that interface with network users and permit the sharing of information, such as files, graphics, and video, and resources, such as printers and disks. One type of application software is called client-server. Client computers send requests for information or requests to use resources to other computers, called servers, that control data and applications. Another type of application software is called peer-to-peer. In a peer-to-peer network, computers send messages and requests directly to one another without a server intermediary. Network software consists of computer programs that establish protocols, or rules, for computers to talk to one another. These protocols are carried out by sending and receiving formatted instructions of data called packets. Protocols make logical connections between network applications, direct the movement of packets through the physical network, and minimize the possibility of collisions between packets sent at the same time. Network hardware is made up of the physical components that connect computers. Two important components are the transmission media that carry the computer's signals, typically on wires or fiber-optic cables, and the network adapter, which accesses the physical media that link computers, receives packets from network software, and transmits instructions and requests to other computers. Transmitted information is in the form of binary digits, or bits (1s and 0s), which the computer's electronic circuitry can process. Network Connections A network has two types of connections: physical connections that let computers directly transmit and receive signals and logical, or virtual, connections that allow computer applications, such as word processors, to exchange information. Physical connections are defined by the medium used to carry the signal, the geometric arrangement of the computers (topology), and the method used to share information. Logical connections are created by network protocols and allow data sharing between applications on different types of computers, such as an Apple Macintosh and an International Business Machines Corporation (IBM) personal computer (PC), in a network. Some logical connections use client-server application software and are primarily for file and printer sharing. The Transmission Control Protocol/Internet Protocol (TCP/IP) suite, originally developed by the United States Department of Defense, is the set of logical connections used by the Internet, the worldwide consortium of computer networks. TCP/IP, based on peer-to-peer application software, creates a connection between any two computers. Media The medium used to transmit information limits the speed of the network, the effective distance between computers, and the network topology. Copper wires and coaxial cable provide transmission speeds of a few thousand bits per second for long distances and about 100 million bits per second (Mbps) for short distances. Optical fibers carry 100 million to 1 billion bits of information per second over long distances. Topology Common topologies used to arrange computers in a network are point-to-point, bus, star, and ring. Point-to-point topology is the simplest, consisting of two connected computers. The bus topology is composed of a single link connected to many computers. All computers on this common connection receive all signals transmitted by any attached computer. The star topology connects many computers to a common hub computer. This hub can be passive, repeating any input to all computers similar to the bus topology, or it can be active, selectively switching inputs to specific destination computers. The ring topology uses multiple links to form a circle of computers. Each link carries information in one direction. Information moves around the ring in sequence from its source to its destination (see Computer Architecture). Local area networks (LANs), which connect computers separated by short distances, such as in an office or a university campus, commonly use bus, star, or ring topologies. Wide area networks (WANs), which connect distant equipment across the country or internationally, often use special leased telephone lines as point-to-point links. Sharing Information When computers share physical connections to transmit information packets, a set of Media Access Control (MAC) protocols are used to allow information to flow smoothly through the network. An efficient MAC protocol ensures

Example Sentences of the Verb Drink for ESL

Example Sentences of the Verb Drink for ESL This page provides example sentences of the verb Drink in all tenses including active and passive forms, as well as conditional and modal forms. Base Form drink / Past Simple drank / Past Participle drunk / Gerund drinking Present Simple He usually drinks four glasses of water a day. Present Simple Passive Water is drunk at meals. Present Continuous She is drinking a gin and tonic. Present Continuous Passive The new wine is being drunk by customers. Present Perfect Peter has drunk three glasses of water this afternoon. Present Perfect Passive All the juice has been drunk. Present Perfect Continuous I have been drinking juice all morning. Past Simple Jack drank a glass of apple juice. Past Simple Passive A glass of apple juice was drunk by that customer. Past Continuous She was drinking some water when the man bumped into her. Past Continuous Passive Water was being drunk when they opened the wine. Past Perfect We had drunk all the water before the order arrived. Past Perfect Passive All the water had been drunk before the order arrived. Past Perfect Continuous We had been drinking our beverages for ten minutes when he finally arrived. Future (will) She will drink orange juice. Future (will) Passive Wine will be drunk by the customers at table six. Future (going to) We are going to drink French wine with our meal. Future (going to) Passive French wine is going to be drunk by the customers at table six. Future Continuous This time tomorrow we will be drinking a nice cold cocktail. Future Perfect He will have drunk three bottles by the end of the evening. Future Possibility He might drink juice. Real Conditional If he drinks wine, I will drive home. Unreal Conditional If he drank wine, I would drive home. Past Unreal Conditional If he had drunk wine, I would have driven home. Present Modal I should drink some tea. Past Modal You should have drunk some milk to calm your stomach. Quiz: Conjugate With Drink Use the verb to drink to conjugate the following sentences. Quiz answers are below. In some cases, more than one answer may be correct. He usually _____ four glasses of water a day.She _____ a gin and tonic at the moment.Peter _____ three glasses of water this afternoon.I _____ juice all morning.A glass of apple juice _____ by that customer.We _____ all the water before the order arrived.She _____ orange juice.We _____ French wine with our meal.If he _____ wine, I would drive home.She _____ some water when the man bumped into her. Quiz Answers drinksis drinkinghas drunkhave been drinkingwas drunkhad drunkwill drinkare going to drinkdrankwas drinking