Outside Class D, C, or B airspace under VFR, there is no requirement to be in voice contact with ATC. Likewise, there is no requirement that the controller provide a handoff for VFR traffic. The flight having progressed to a point outside, the controller is advising that the pilot is no longer required to maintain contact. The flight is then in Class E airspace. The pilot may very often choose to continue the flight out of radio contact until approaching another airspace where contact is required. The airspace around CYOW is a little complicated but fundamentally is a Class C primary airport with class D airspace around it, and radar available as usual for a Class C.
In the US, the instruction would be "radar services terminated, squawk 1200, frequency change approved".
Under IFR, the aircraft would be in contact with ATC for the entire flight and would be handed to the next appropriate controller all the way as they move from one controller's coverage area to the next.