A criminal case begins when the District Attorney's Office, on behalf of the State of Oregon, files a charging document (a complaint, information or indictment) against the defendant.
A crime is a felony if the maximum penalty includes a sentence of more than one year of incarceration. Felonies include, for example, possession, manufacturing and delivery of drugs, robbery, burglary, theft in the first degree, identity theft, assault in the first degree/second degree/third degree; and most sexual assault crimes.
A crime is a misdemeanor if the defendant cannot be ordered to serve more than one year in jail. Common misdemeanors include most assault in the fourth degree cases, harassment, menacing, theft in the second degree/third degree, criminal trespass, and most DUII cases.