Usually, Canadian Universities ask for a 4-year Bachelor's degree as a minimum requirement. This is usually called B.Sc. Major option.
Quote from Carleton, Computer Science:
Will a Major Degree Prevent Me From Going On to Do Graduate Studies?
Not necessarily. Many universities indicate that they require an
Honours degree or equivalent to get into a Master’s program, so the
Honours degree is better if you intend to apply for a Masters or Ph.D.
in computer science. However, a student with high grades from a
Major degree will likely be considered for graduate work.
So, B.Sc. Honours compared to B.Sc. Major is intended (partially) to prepare you better for a graduate school. It usually involves some research component and stricter selection of the required courses. Another quote from McGill:
Honours programs typically involve an even higher degree of
specialization than majors, include supervised research, and require
students to maintain a high academic standard. An honours program
provides solid preparation for graduate school.
So, do you have to have Honours to enter graduate school? No. Would it have helped? Probably, yes. Not necessarily. I would say that even if the program that you are anxious to apply to requires B.Sc. Honours, you might approach them and convince that you can succeed in the graduate studies by good GPA, relevant course selection, impressive letter of intent, exceptional recommendation letters, etc.
Also, there would be plenty of programs that certainly do not ask for Honours degree as their minimum requirement. Say:
