Interpreted language

In an interpreted language your source code is read in command by command by a software tool, which is called the Interpreter and executed. Without the Interpreter your programs will not run. There are almost always Compilers for the language you are using.

These have the advantage of creating faster and standalone proghrams out of your source, as the reading in and interpreting creates additional overhead, and the source code is harder to optimize.

One exception may be Euphoria which is only interpreted, but claims to be as fast as (or even faster) than traditional compiled source.