1、翻译是把一种语言表达的意义用另一种语言传达出来，以达到沟通思想情感、传播文化知识、促进社会文明，特别是推动译语文化兴旺昌盛的目的。
Translation is an activity of reproducing in one language the ideas which have been expressed in another language.
翻译理论家Eugene A. Nida  Alexander Fraser Tytler
2. Scope of Translation
按语言分类in terms of languages：
语内翻译（intralingual translation）语际翻译（interlingual translation）
按活动形式分类in terms of the mode：笔译（translation）口译（oral interpretation）连续传译（consecutive translation） 和同声传译（simultaneous translation）
按翻译材料的文体分类in terms of materials to be translated：应用文体翻译 科技文体翻译、论述文体翻译新闻文体翻译、艺术文体翻译
按处理方式分类in terms of disposal：(全译full-text translation, 节译abridged translation, 摘译adapted translation编译compilation compile译述translate freely )
3. Criteria in China
B. Yan Fu’s (严复) “three character guide”, which was first proposed in 1898 in the Preface of his translation of the book Natural Selection(《天演论》), is the principle of “faithfulness, expressiveness, and elegance” (信、达、雅).
Some revisions such as faithfulness, expressiveness and closeness (信、达、切); faithfulness, expressiveness and fitness (信、达、贴),
D. Fu Lei’s (傅雷) spiritual conformity/resemblance in spirit （神似)
E. Qian Zhongshu (钱钟书) transmigration (化境)
鲁迅：翻译：力求其易解, 保存原作的丰姿。反对牛头不对马嘴，提出“宁信而不顺”之原则。
林语堂的“忠实、通顺、美”
瞿秋白的“信顺统一”
许渊冲的“音美、形美、意美（三美）”
Criteria for beginners:  Faithfulness & Smoothness
4.Three Principles of Translation（翻译法则）:
十八世纪末的英国学者亚历山大·泰特勒(Alexander Fraser Tytler, 1747-1814)。他在《论翻译的原则》(Essay on the Principles of Translation)一书中提出了著名的翻译三原则：
（1）译文应完全复写出原作的思想（A translation should give a complete transcript of the ideas of the original work.）
（2）译文的风格和笔调应与原文的性质相同(The style and manner of writing should be of the same character as that of the original.)
（3）译文应和原作同样流畅(A translation should have all the ease of the original composition.）
5. Nature of Translation
Translation is a science,an art,a craft,a skill,an operation.,a language activity,communication
1) 翻译是跨语言(cross-linguistic)，跨文化(cross-cultural)，跨社会(cross-social)的交际活动。
2) 翻译是一种语言文化承载的意义转换到另一种语言文化中的跨语言，跨文化的交际活动。
Translation is a representation or recreation in one language of what is written or said in another language.
  翻译的本质是释义,是意义的转换. Translation is always meaning-based
奈达(Eugene.A.Nida):翻译是指从语义到文体在译语中用最切近而又最自然的对等语再现原文的信息.Translating consists in reproducing in the receptor/target language, the closet natural equivalent of the source language message, first in terms of meaning, and secondly in terms of style.
(3) 翻译是科学(science)，是艺术(art)，是技能(craft)
翻译是科学，因为它涉及思维和语言,反映了存在与认识,主体与客体的关系,这种关系可用受一定规律支配的语言加以描述,翻译有科学规律可循,所以是科学。 translation is a kind of science because it has a whole set of rules governing it and certain objective laws to go by in the process of translating just as other sciences do.
翻译是艺术，因为翻译是译者对原文再创造的过程。译者不可避免地带有自己的主观彩，有他自己的独创性。translation is also an art, a bilingual art. Like painting, translation enables us to reproduce the fine thought of somebody, not in colors, but in words, in words of a different language.
翻译是技能，译者需采用增词，减词，切分,转换等方法。besides, it’s also a craft, because in translation, certain skills and technique are needed in order to attain clearness of style, and fluency in language.
6. The Process of Translation
A. Preparation: basic knowledge about both  languages as well as the background knowledge; basic skills in translation are necessary;
B. Comprehension: understanding accurately the meaning of the source language; How?
C. Expression/Representation: try to express the meaning in idiomatic Chinese;
D. Revision /proofreading: check again and again to polish the language.
content的中文翻译STEP 1 The Stage of Understanding
The understanding in the process of translation is different from the understanding in our daily reading.
First of all, the aim of the understanding in the process of translation is representing (表达) the content faithfully, so we have to try to understand the text completely, deeply and in detail. 
Secondly,  in the understanding in translation, we are thinking in two languages, and in two
ways. So, it’s very complicated.
STEP 2 The Stage of Representation
1.直译（Literal Translation）
Literal Translation means  translating according to the surface meaning and keeping the structures of sentences. Literal translation keeps both the content and the form of the original work.
2.意译 ( Liberal Translation)
Because of the different way of thinking some of the English sentences cannot be translated in the literal way, they can only be translated in the liberal way. In liberal translation the form can be neglected but the content must always be faithful.