High-level programs cannot be executed directly, they must be compiled in advance of execution, or interpreted by a runtime program.
the program written in high level language is called "source program"
A compiler. We can also use an interpreter to translate high-level code as it is executed, however in order to create a stand-alone executable we must use a compiler. A compiler is simply a program that translates high-level code to a lower-level code (but not necessarily machine code). For instance, the Java compiler emits Java byte code which is suitable for interpretation by the Java virtual machine.
the program written in high level language is called "source program"
High-level and low-level.
There is no such program. Low level languages cannot be converted to high level languages. It's one-way only.
When it is executed.
An interpreter.
Explain briefly the meaning of an input-output (1/0) bound program, and a processor (CPU) bound program.
Not necessarily. Any language with an object-oriented approach will be a high-level language, but a high-level language does not have to use an object-oriented approach.
Unless your particular C implementation allows for direct writing of assembly code, you can't. C is a high-level language and you usually cannot directly issue instructions to the processor. The assembly languages are a set of architecture-specific commands that can be directly executed by a processor.
A computer program contains instructions, to be executed by a computer.
An executable file (*.exe)