The following article compares medicaid and public option, may give some insight about the public option
http://www.differencebetween.net/science/health/difference-between-medicaid-and-public-option/
For the analog format, the translation of data is in electric pulses which varies in amplitude while for the digital format, the translation of data is in the binary format with two distinct amplitudes represent each bit.
Excerpt from the article...