What's the difference between Canada and USA's senior secondary and post secondary education system ?

For example I've heard in Canada you have to take specific subjects after 10th standard to specialise in during 11th and 12th standard to gain entry to the bachelor's programs you want to be in

Is this true ? And can someone in Canada change those subjects (taken in 11th and 12th) later on after graduating high school if they change their mind about what they want to study ?

Whereas in the USA there's less focus on specialisation as far as I've seen

Submitted July 05, 2019 at 08:26PM by Mewto1k https://ift.tt/32eC7Kj