Foreign nationals who have committed to working, studying or making their home in Canada will be permitted to enter Canada by air or land. IRCC will soon be putting procedures in place to ensure this.
Canadian citizens, permanent residents, as well as some foreign nationals travelling from the US who have been in the US for at least 14 days and are asymptomatic, will be able to enter Canada by air.
All travelers, with some exceptions, including Canadian citizens and permanent residents, and temporary foreign workers who enter Canada by air or land will undergo the necessary health checks and must isolate for 14 days upon arrival in Canada.