1. Canada is sending up to 10 aircraft and 600 personnel
The Prime Minister's Office said that Canada's contribution will include one CC-150 Polaris air-to-air refuelling aircraft, two CP-140 Aurora surveillance aircraft, one dedicated airlift aircraft for refuelling, air surveillance and transportation, and up to six CF-18 Hornet fighter jets. There will be about 280 aircrew and other personnel to support the Polaris, Aurora and airlift planes, and another 320 aircrew and personnel for the fighter jets.
2. There's a deadline on the mission
The government initially offered up to 69 military advisers for 30 days, of which they said 29 were on the ground this week. That pledge has been extended, but the Canadian contribution has a six-month limit.
3. Canadians will attack by air, not land
The government's motion specifically rules out ground combat operations.
4. Air combat over Syria is an option
Harper pledged to strike ISIS "where — and only where — Canada has the clear support of the government of that country." That doesn't include Syria right now, he said, but Canada would expand its airstrikes to include Syria if that changes.
5. Harper doesn't expect to eliminate ISIS
In his speech, Harper made it clear that he doesn't expect to bring an end to ISIS, also known as ISIL. He differs there from U.S. President Barack Obama, who aims to "ultimately destroy" ISIS.
"We intend to significantly degrade the capabilities of ISIL," he told MPs. "Specifically, its ability either to engage in military movements of scale or to operate bases in the open."
"But, again, to be clear," he said later in his speech, "while ISIL will not be eliminated, the risks presented from the territory in which it operates will be significantly reduced."
Mobile users, view a Canadian Press graphic on CF-18s.