Indictable Offences are very serious offences according to the Criminal Code of Canada. These offenses have a greater penalty. Most offences that require prosecution by indictment also means you have to undergo trial by jury and, more often than not, a preliminary hearing is needed.
Summary Conviction Offences have lighter penalties, such as fines or a maximum imprisonment of six months.
Sometimes, depending on the crime, there can be hybrid offenses where the sentence combines both indictable offenses and summary conviction offenses.