Why does Raspberry Pi need an OS to work?

I am just new to world of electronics. I was just looking about Raspberry Pi as I want to work on it, but a thing that I found that everyone is installing an OS first on the Raspberry Pi. I have …

ImportError No module named pyaudio

I am writing a program in Python on RaspberryPi, But I am getting an error ImportError No module named pyaudio After that I tried git clone http://people.csail.mit.edu/hubert/git/pyaudio.git but …