Most students, after completing university or college, proceed to the working world. They might take a year off to travel, but generally, they start to look for jobs or work in their fields.
Some students go on to more schooling.
When people in Canada talk about graduate school, they are referring to degrees that only students who have completed a bachelor degree can take.
The first level of degree after a bachelor is a master's degree. An example of this would be a master's of business administration or MBA.
The next level would be a doctorate degree, or a Ph.D.