computer is a machine that manipulates data according to a list of instructions.
The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers(PC).[1] Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices — for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.
有道翻译：
计算机是一种机器操作数据根据指令的列表
第一个设备,像现代计算机日期到20世纪中叶(1940 - 1945),尽管计算机概念和各种设备类似电脑以前。早期的电子计算机是一个大房间的大小,消耗更多的能源为几百现代个人电脑(PC)。[1]现代电脑都基于微型集成电路和有数百万到数十亿倍,更有能力,同时占用空间的一小部分。[2]今天,简单的电脑可以小到足以放进一个手表和从一个手表电池供电。个人电脑,以不同的形式,是信息时代的象征,是很多人认为的“电脑”;然而,最常见的计算机在使用今天是嵌入式计算机。嵌入式电脑虽小,简单的设备,用于控制其他设备——例如,它们可能被发现
Computer Science
Computer science (or computing science) is the study of the theoretical foundations of information and computation, and of practical techniques for their implementation and application in computer systems. It is frequently described as the systematic study of algorithmic processes that describe and transform information. According to Peter J. Denning, the fundamental question underlying computer science is, "What can be (efficiently) automated?" Computer science has many sub-fields; some, such as computer graphics, emphasize the computation of specific results, while others, such as computational complexity theory, study the properties of computational problems. Still others focus on the challenges in implementing computations. For example, programming language theory studies approaches to describing computations, while computer programming applies specific programming languages to solve specific computational problems, and human-computer interaction focuses on the challenges in making computers and computations useful, usable, and universally accessible to people.
The general public sometimes confuses computer science with vocational areas that deal with computers (such as information technology), or think that it relates to their own experience of computers, which typically involves activities such as gaming, web-browsing, and word-processing. However, the focus of computer science is more on understanding the properties of the programs used to implement software such as games and web-browsers, and using that understanding to create new programs or improve existing ones.
History
The early foundations of what would become computer science predate the invention of the modern digital computer. Machines for calculating fixed numerical tasks, such as the abacus, have existed since antiquity. Wilhelm Schickard built the first mechanical calculator in 1623. Charles Babbage designed a difference engine in Victorian times helped by Ada Lovelace. Around 1900, punch-card machines were introduced. However, all of these machines were constrained to perform a single task, or at best some subset of all possible tasks.
During the 1940s, as newer and more powerful computing machines were developed, the term computer came to refer to the machines rather than their human predecessors. As it became clear that computers could be used for more than just mathematical calculations, the field of computer science broadened to study computation in general. Computer science began to be established as a distinct academic discipline in the 1950s and early 1960s, with the creation of the first computer science departments and degree programs. Since practical computers became available, many applications of computing have become distinct areas of study in their own right.
Although many initially believed it impossible that computers themselves could actually be a scientific field of study, in the late fifties it gradually became accepted among the greater academic population. It is the now well-known IBM brand that formed part of the computer science revolution during this time. IBM (short for International Business Machines) released the IBM 704 and later the IBM 709 computers, which were widely used during the exploration period of such devices. "Still, working with the IBM [computer] was frustrating...if you had misplaced as much as one letter in one instruction, the program would crash, and you would have to start the whole process over again". During the late 1950s, the computer science discipline was very much in its developmental stages, and such issues were commonplace.
Time has seen significant improvements in the usability and effectiveness of computer science technology. Modern society has seen a significant shift from computers being used solely by experts or professionals to a more widespread user base.
Major Achievements
Despite its relatively short history as a formal academic discipline, computer science has made a number of fundamental contributions to science and society. These include:
Started the "digital revolution", which includes the current Information Age and the Internet.
A formal definition of computation and computability, and proof that there are computationally unsolvable and intractable problems.
The concept of a programming language, a tool for the precise expression of methodological information at various levels of abstraction.
In cryptography, breaking the Enigma machine was an important factor contributing to the Allied victory in World War II.
Scientific computing enabled advanced study of the mind, and mapping the human genome became possible with Human Genome Project. Distributed computing projects such as Folding@home explore protein folding.
Algorithmic trading has increased the efficiency and liquidity of financial markets by using artificial intelligence, machine learning, and other statistical and numerical techniques on a large scale.
Fields of Computer Science
As a discipline, computer science spans a range of topics from theoretical studies of algorithms and the limits of computation to the practical issues of implementing computing systems in hardware and software. The Computer Sciences Accreditation Board (CSAB) – which is made up of representatives of the Association for Computing Machinery (ACM), the Institute of Electrical and Electronics Engineers Computer Society, and the Association for Information Systems – identifies four areas that it considers crucial to the discipline of computer science: theory of computation, algorithms and data structures, programming methodology and languages, and computer elements and architecture. In addition to these four areas, CSAB also identifies fields such as software engineering, artificial intelligence, computer networking and communication, database systems, parallel computation, distributed computation, computer-human interaction, computer graphics, operating systems, and numerical and symbolic computation as being important areas of computer science.
Theoretical Computer Science
The broader field of theoretical computer science encompasses both the classical theory of computation and a wide range of other topics that focus on the more abstract, logical, and mathematical aspects of computing.
Theory of Computation
The study of the theory of computation is focused on answering fundamental questions about what can be computed, and what amount of resources are required to perform those computations. In an effort to answer the first question, computability theory examines which computational problems are solvable on various theoretical models of computation. The second question is addressed by computational complexity theory, which studies the time and space costs associated with different approaches to solving a computational problem.
The famous "P=NP?" problem, one of the Millennium Prize Problems, is an open problem in the theory of computation.
Relationship with Other Fields
Despite its name, a significant amount of computer science does not involve the study of computers themselves. Because of this, several alternative names have been proposed. Certain departments of major universities prefer the term computing science, to emphasize precisely that difference. Danish scientist Peter Naur suggested the term datalogy, to reflect the fact that the scientific discipline revolves around data and data treatment, while not necessarily involving computers. The first scientific institution to use the term was the Department of Datalogy at the University of Copenhagen, founded in 1969, with Peter Naur being the first professor in datalogy. The term is used mainly in the Scandinavian countries. Also, in the early days of computing, a number of terms for the practitioners of the field of computing were suggested in the Communications of the ACM – turingineer, turologist, flow-charts-man, applied meta-mathematician, and applied epistemologist. Three months later in the same journal, comptologist was suggested, followed next year by hypologist. The term computics has also been suggested. Informatik was a term used in Europe with more frequency.
The renowned computer scientist Edsger Dijkstra stated, "Computer science is no more about computers than astronomy is about telescopes." The design and deployment of computers and computer systems is generally considered the province of disciplines other than computer science. For example, the study of computer hardware is usually considered part of computer engineering, while the study of commercial computer systems and their deployment is often called information technology or information systems. However, there has been much cross-fertilization of ideas between the various computer-related disciplines. Computer science research has also often crossed into other disciplines, such as cognitive science, economics, mathematics, physics (see quantum computing), and linguistics.
Computer science is considered by some to have a much closer relationship with mathematics than many scientific disciplines, with some observers saying that computing is a mathematical science. Early computer science was strongly influenced by the work of mathematicians such as Kurt Gödel and Alan Turing, and there continues to be a useful interchange of ideas between the two fields in areas such as mathematical logic, category theory, domain theory, and algebra.
The relationship between computer science and software engineering is a contentious issue, which is further muddied by disputes over what the term "software engineering" means, and how computer science is defined. David Parnas, taking a cue from the relationship between other engineering and science disciplines, has claimed that the principal focus of computer science is studying the properties of computation in general, while the principal focus of software engineering is the design of specific computations to achieve practical goals, making the two separate but complementary disciplines.
The academic, political, and funding aspects of computer science tend to depend on whether a department formed with a mathematical emphasis or with an engineering emphasis. Computer science departments with a mathematics emphasis and with a numerical orientation consider alignment computational science. Both types of departments tend to make efforts to bridge the field educationally if not across all research.
Computer Science Education
Some universities teach computer science as a theoretical study of computation and algorithmic reasoning. These programs often feature the theory of computation, analysis of algorithms, formal methods, concurrency theory, databases, computer graphics and systems analysis, among others. They typically also teach computer programming, but treat it as a vessel for the support of other fields of computer science rather than a central focus of high-level study.
Other colleges and universities, as well as secondary schools and vocational programs that teach computer science, emphasize the practice of advanced programming rather than the theory of algorithms and computation in their computer science curricula. Such curricula tend to focus on those skills that are important to workers entering the software industry. The practical aspects of computer programming are often referred to as software engineering. However, there is a lot of disagreement over the meaning of the term, and whether or not it is the same thing as programming.
Some, maintaining the viewpoint that study of the social science such as philosophy or psychology outweighs the technology of computer, claim that the latter brings more social problems than the former. Although I party agree with this point, as for me, the importance of computer can not be ignored, especially considering the advantages of chatting and medicine diagnose online.
Initially, one issue is that the digital technology of computer has many desirable impacts on all realm of life. For instance, digital technology has spawned great advances in medicine and physics, helping us enhance our health, prolong our life, and improve our understanding of the material world. Similarly, digital automation has emancipated painter, composer and architects, by relegating repetitive task to computer and by saving their time to expand creative possibilities. Perhaps most importantly, however, the internet brought about by the development of computer technology has made possible universal access to information for the public, thereby providing a democratizing influence on our culture.
To back up my point, it could be relevant to include another cause that the training experience of computer skill can improve the prospect of employment. The students who major in computer course such as information technology or writing programming language are more competitive in job hunting. Over one hundred studies carried out in the ten major cities in the USA revealed that these students can achieve a high employment rate(78.65%). To the contrary, these who are equipped with such academic knowledge as philosophy, linguistic or economics have few job opportunities, and it turns out that they have take jobs below their abilities.
From what has been mentioned above comes this natural summary that we should pay attention to the study and development of computer technology.
一些人持有这样一种观点，诸如哲学或者心理学的社会科学比计算机科学重要，他们认为后者比前者带来更多的社会问题。我对这种观点持保留态度，我认为，计算机的重要性也不能被忽略，特别是考虑到网上聊天和网上诊断的便利性。
首先，电脑数字技术给我们生活的各方面都带来了令人满意的影响。比如说，数字技术对医药和物理都起了重大的推动作用，它帮助我们加强了我们的健康，延长了我们的寿命，并且改变了我们对物质世界的认识。同样，通过把重复的工作交给计算机，数字自动化也解放了画家，作曲家和建筑设计师，他们可以有更多的时间去进行创作。然而，可能是最重要的，计算机发展带来的互联网给我们大众提供了了解信息的途径，因此为我们的文化提供了民主化的影响。
另一个相关的例子也可以支持我的观点，计算机技能的培训经历可以改变我们的就业前景。那些主修计算机课程诸如信息技术或者编程的学生在寻找工作时更有竞争力。在美国10个大城市进行的超过100份调查显示，这些学生可以获得很高的就业率（78.65%）。相反，那些学习了学术性知识例如哲学，语言学或者经济学的学生，则就业机会较少，并且找到的工作都低于他们的能力。
从这些提到的例子，我们可以自然得到结论，我们必须关注计算机技术的发展和研究。
Computers
Nowadays, computer plays a more and more important role in our lives. We can't live without it. However, everything has two sides. So does computer. On the one hand, computer has brought a lot of convenience to our daily lives. We can search imformation for our essays on baidu, discuss issues with friends on qq, and use wikipedia to find professional answers for our problems. On the other hand, computer truly has some negetive effects on some people's lives. Some children can't control themselves so much, so they often spoil hours on the computer games and chatting with friends about some useless topics. Also, there are a lot of imformation online that is not appropiate for young children. All in all, although computer brings all kinds of problems, we should still admit what it has done to improve our daily lives.
现在,电脑在我们的生活中发挥着越来越重要的作用.没有电脑,我们不能生活.然后,每件事都有两面性,电脑也如此.一方面,电脑给我们的日常生活带来了许多方便.我们可以用百度搜索我们想要的文章,和朋友们在上讨论时事,并且用维基百科来找我们的问题的个性答案.在另一方面,电脑在一些人的生活中却带来相反的结果.一些孩子沉迷电脑不能自拔,所以他们几个小时泡在电脑游戏上并且和朋友聊一些无意义的话题.而且,在网络上有一些儿童不宜的信息.总之,尽管电脑带来各种问题,我们仍然应该承认电脑已经改善了我们的日常生活.
