What is the difference between compiled language and interpreted language?

Answer 1

A compiled language is written and then run through a compiler which checks its syntax and compresses it into a binary executable. Since an interpreted language is not compiled, it must be checked for errors at run-time, which makes it quite a bit slower than a compiled language (like C or Java). Perl is an example of an interpreted language. Remember, though, that just because a language is interpreted doesn't necessarily mean it is not full-featured, or simplistic. Perl can get very complex and very cryptic, very quickly.

Answer 2

Interpretive Basic executes as is. When the program is ran each instruction is looked at, evaluated, and then executed by the interpreter. Compiled Basis on the other hand, is a set of machine instructions that were created from the Basic source code by the compiler. Being in machine code makes the compiled code run 10-15 times faster.

Answer 3

A compiled computer language outputs a program file that is directly understandable by the CPU in a computer and is ready to be run. It is in what is called binary format, is not readable by (most) humans, but is directly understood by the computer.

An interpreted computer language generally outputs a program in a manner that is not directly understood by the computer CPU. It must be turned into machine readable binary (compiled) when you run it. The file is often human readable and understandable, but is not understood by the computer.

A good way to separate a compiled language from an interpreted language is to look at what happens to the source code and how that source code is turned into a running program.

In a compiled language, the source code files are run through a compiler ONCE, and outputs a single fixed "binary". Typically, this binary is in the machine code of the architecture the compiler is on, but it may also be in another architecture's machine code (for "cross-compilers"), or even in a synthetic architecture (as in the case with bytecodes, as typical for Java or Python). That binary can then be directly run on any compatible platform. The key here is that the conversion to a "runnable" format is done only once, and that the only thing needed to run the program on a suitable platform is the binary. The source code and compiler only need to be available when the binary is originally being created; afterwards, they aren't needed.

For an interpreted language, each and every time the program is run, the interpreter has to parse the source code files, and then creates an internal representation of the program. The interpreter itself decides how the source code should execute. After a run, there is nothing left except the source code, so any optimizations that the interpreter makes during the run are lost, and will have to be redone the next time the program is run. The major distinction here is that in order for an interpreted program to run, BOTH the source code AND the interpreter must be present, each and every time the program is to be run.