is arduino is best for embedded?

Answer 1

The AVR is a good general purpose chip. The arduino abstraction layer makes it easier to program it sacrificing performances in a reasonable way.
There are many alternatives that, depending on the task you want to accomplish, may be cheaper, faster, less power hungry than an arduino.

Answer 2

no it's not best for production but it is good for prototyping and hobby jobs

Answer 3

what are all programming languages used for production products?