Under the Criminal Code of Canada, there are three types of offences: summary conviction offences, indictable offences, and those offences where the Crown may elect to proceed by summary conviction or by indictment. For those types of Crown election offences, they are often referred to as "hybrid offences". The simplest explanation of the difference between summary conviction offences and indictable offences is that the former is less serious and the latter is more serious.
Summary Conviction Offences
Summary conviction offences include the least serious offences under the Criminal Code of Canada. Relatively speaking to the number of offences under the Criminal Code, there are actually very few pure summary conviction offences. Those pure summary conviction offences include: possession of marijuana under 30 grams, solicitation of prostitution, being found in a common bawdy house, etc.
There are unique aspects that apply to summary conviction offences that do not apply to indictable offences include. For example, in summary conviction offences, a six month limitation period to proceed by way of summary conviction. Another unique aspect to summary conviction offences is that a person charged with a pure summary conviction offence (not hybrid) is not required to submit their fingerprints with police upon or after arrest or conviction. Summary conviction offences are appealed in the Superior Court of the relevant jurisdiction (and not directly to the Court of Appeal). In Ontario, those appeals take place in the Ontario Superior Court of Justice. Summary conviction offences generally carry a maximum penalty of six months in jail, although some summary (hybrid) offences have a maximum of eighteen months in jail (e.g. assault causing bodily harm, assault with a weapon, forcible confinement, sexual assault). A person is not entitled to a jury trial or to have their case heard in the Superior Court of Justice (unless it is being heard alongside an indictable offence at the same time).
Indictable offences are the most serious of criminal offences and would include murder, acts of terrorism, robbery, drug trafficking, robbery, treason, certain types of sexual assault, and other very serious criminal acts. As one could imagine, the sentences for these types of offences is very serious and often with maximum penalties of life imprisonment. Anyone charged with these sorts of offences usually has the right to chose their mode of trial: judge alone in Provincial Court without a preliminary hearing, judge alone in Superior Court with or without a preliminary hearing, or Judge and Jury with or without a preliminary hearing. Not everyone who is facing an indictable offence is entitled to a preliminary hearing or a judge and jury trial (those exceptions are set out in section 553 of the Criminal Code). Similarly, not every type of offence permits the accused to elect to have a judge without a jury unless the prosecutor consents.
There is no limitation period for indictable offences and a person can be charged, tried, acquitted or convicted at any time the police wish to proceed with the charges provided there is a sufficient basis for doing so.