从http://www.quora.com/What-is-the-difference-between-compiled-and-interpreted-programming-languages

There is no difference, because “compiled programming language” and “interpreted programming language” aren’t meaningful concepts. Any programming language, and I really mean any, can be interpreted or compiled. Thus, interpretation and compilation are implementation techniques, not attributes of languages. Interpretation is a technique whereby another program, the interpreter, performs operations on behalf of the program being interpreted in order to run it. If you can imagine reading a program and doing what it says to do step-by-step, say on a piece of scratch paper, that’s just what an interpreter does as well. A common reason to interpret a program is that interpreters are relatively easy to write. Another reason is that an interpreter can monitor what a program tries to do as it runs, to enforce a policy, say, for security. Compilation is a technique whereby a program written in one language (the “source language”) is translated into a program in another language (the “object language”), which hopefully means the same thing as the original program. While doing the translation, it is common for the compiler to also try to transform the program in ways that will make the object program faster (without changing its meaning!). A common reason to compile a program is that there’s some good way to run programs in the object language quickly and without the overhead of interpreting the source language along the way. You may have guessed, based on the above definitions, that these two implementation techniques are not mutually exclusive, and may even be complementary. Traditionally, the object language of a compiler was machine code or something similar, which refers to any number of programming languages understood by particular computer CPUs. The machine code would then run “on the metal” (though one might see, if one looks closely enough, that the “metal” works a lot like an interpreter). Today, however, it’s very common to use a compiler to generate object code that is meant to be interpreted—for example, this is how Java used to (and sometimes still does) work. There are compilers that translate other languages to JavaScript, which is then often run in a web browser, which might interpret the JavaScript, or compile it a virtual machine or native code. We also have interpreters for machine code, which can be used to emulate one kind of hardware on another. Or, one might use a compiler to generate object code that is then the source code for another compiler, which might even compile code in memory just in time for it to run, which in turn . . . you get the idea. There are many ways to combine these concepts.

编译语言是这样一种语言:程序一旦编译，就用目标机器的指令来表达。例如，源代码中的加法“+”操作可以直接转换为机器代码中的“ADD”指令。

解释型语言是指指令不直接由目标机器执行，而是由其他程序(通常用本机语言编写)读取和执行的语言。例如，相同的“+”操作将在运行时被解释器识别，然后调用它自己的“add(a,b)”函数，并使用适当的参数，然后执行机器代码“add”指令。

你可以在编译语言中做你在解释语言中可以做的任何事情，反之亦然——它们都是图灵完备的。然而，这两种方法在实施和使用方面都有优点和缺点。

我将完全概括(纯粹主义者原谅我!)，但大致来说，以下是编译语言的优点:

通过直接使用目标计算机的本机代码获得更快的性能 有机会在编译阶段应用相当强大的优化

下面是解释型语言的优点:

更容易实现(编写好的编译器非常困难!!) 不需要运行编译阶段:可以直接“动态”执行代码 是否可以更方便地使用动态语言

注意，字节码编译等现代技术增加了一些额外的复杂性——这里发生的情况是，编译器的目标是一个与底层硬件不同的“虚拟机”。这些虚拟机指令可以在稍后阶段再次编译，以获得本机代码(例如，由Java JVM JIT编译器完成)。

语言本身既不编译也不解释，只有语言的特定实现才是。Java就是一个很好的例子。有一个基于字节码的平台(JVM)、一个本机编译器(gcj)和一个用于Java超集(bsh)的互用器。那么Java现在是什么呢?字节码编译，本机编译还是解释?

其他既编译又解释的语言有Scala、Haskell或Ocaml。每种语言都有一个交互式解释器，以及一个字节码或本机机器码的编译器。

所以一般来说，用“编译型”和“解释型”来划分语言并没有多大意义。

极端和简单的情况:

A compiler will produce a binary executable in the target machine's native executable format. This binary file contains all required resources except for system libraries; it's ready to run with no further preparation and processing and it runs like lightning because the code is the native code for the CPU on the target machine. An interpreter will present the user with a prompt in a loop where he can enter statements or code, and upon hitting RUN or the equivalent the interpreter will examine, scan, parse and interpretatively execute each line until the program runs to a stopping point or an error. Because each line is treated on its own and the interpreter doesn't "learn" anything from having seen the line before, the effort of converting human-readable language to machine instructions is incurred every time for every line, so it's dog slow. On the bright side, the user can inspect and otherwise interact with his program in all kinds of ways: Changing variables, changing code, running in trace or debug modes... whatever.

说完了这些，让我来解释一下，生活不再那么简单了。例如,

Many interpreters will pre-compile the code they're given so the translation step doesn't have to be repeated again and again. Some compilers compile not to CPU-specific machine instructions but to bytecode, a kind of artificial machine code for a ficticious machine. This makes the compiled program a bit more portable, but requires a bytecode interpreter on every target system. The bytecode interpreters (I'm looking at Java here) recently tend to re-compile the bytecode they get for the CPU of the target section just before execution (called JIT). To save time, this is often only done for code that runs often (hotspots). Some systems that look and act like interpreters (Clojure, for instance) compile any code they get, immediately, but allow interactive access to the program's environment. That's basically the convenience of interpreters with the speed of binary compilation. Some compilers don't really compile, they just pre-digest and compress code. I heard a while back that's how Perl works. So sometimes the compiler is just doing a bit of the work and most of it is still interpretation.

最后，现在，解释和编译是一种权衡，花费(一次)编译的时间通常会获得更好的运行时性能，但解释环境提供了更多的交互机会。编译与解释主要是“理解”程序的工作如何在不同的过程之间划分的问题，而如今，由于语言和产品试图提供两者的最佳服务，这条界线有点模糊。

简短的(不精确的)定义:

编译语言:将整个程序立即转换为机器代码，然后由CPU运行机器代码。

解释语言:逐行读取程序，一旦读取一行，CPU就会执行该行的机器指令。

但实际上，现在很少有语言是纯编译或纯解释的，它们通常是混合的。想要更详细的图片描述，请看这个帖子:

编译和解释的区别是什么?

或者是我后来的博客:

https://orangejuiceliberationfront.com/the-difference-between-compiler-and-interpreter/

从http://www.quora.com/What-is-the-difference-between-compiled-and-interpreted-programming-languages

There is no difference, because “compiled programming language” and “interpreted programming language” aren’t meaningful concepts. Any programming language, and I really mean any, can be interpreted or compiled. Thus, interpretation and compilation are implementation techniques, not attributes of languages. Interpretation is a technique whereby another program, the interpreter, performs operations on behalf of the program being interpreted in order to run it. If you can imagine reading a program and doing what it says to do step-by-step, say on a piece of scratch paper, that’s just what an interpreter does as well. A common reason to interpret a program is that interpreters are relatively easy to write. Another reason is that an interpreter can monitor what a program tries to do as it runs, to enforce a policy, say, for security. Compilation is a technique whereby a program written in one language (the “source language”) is translated into a program in another language (the “object language”), which hopefully means the same thing as the original program. While doing the translation, it is common for the compiler to also try to transform the program in ways that will make the object program faster (without changing its meaning!). A common reason to compile a program is that there’s some good way to run programs in the object language quickly and without the overhead of interpreting the source language along the way. You may have guessed, based on the above definitions, that these two implementation techniques are not mutually exclusive, and may even be complementary. Traditionally, the object language of a compiler was machine code or something similar, which refers to any number of programming languages understood by particular computer CPUs. The machine code would then run “on the metal” (though one might see, if one looks closely enough, that the “metal” works a lot like an interpreter). Today, however, it’s very common to use a compiler to generate object code that is meant to be interpreted—for example, this is how Java used to (and sometimes still does) work. There are compilers that translate other languages to JavaScript, which is then often run in a web browser, which might interpret the JavaScript, or compile it a virtual machine or native code. We also have interpreters for machine code, which can be used to emulate one kind of hardware on another. Or, one might use a compiler to generate object code that is then the source code for another compiler, which might even compile code in memory just in time for it to run, which in turn . . . you get the idea. There are many ways to combine these concepts.