Languages like C and C++ compile down directly to machine code, and the resulting machine code is run from then on the bare metal without any further translation.
Interpreted languages such as Python or Ruby (or languages that run on a VM, like Java) go through an interpretation step _every time_ they are run that translates them down to machine language.
This gives compiled languages an inherent advantage in terms of runtime performance; programs written in these languages don't have the overhead of translating to machine code at runtime. This is typically why people advocate "next to bare metal" as having better performance.
Interpreted languages such as Python or Ruby (or languages that run on a VM, like Java) go through an interpretation step _every time_ they are run that translates them down to machine language.
This gives compiled languages an inherent advantage in terms of runtime performance; programs written in these languages don't have the overhead of translating to machine code at runtime. This is typically why people advocate "next to bare metal" as having better performance.