How will college admissions officers know my international school's academic rigor?

Applying to College
1

Hello! I’m an international student from South America. I go to a pretty good private school, one of the top 3 last year, and very few students achieve a final grade above 90% (4.0) in any class. We have to take about 17 year-round classes in every grade of high school, and it’s a pretty challenging preparatory school. The question is: how will they know that my school is hard? Will they look at my grades the same way as they look at a Brazilian public schooler grades (public schools here are known to be easier)?
Thank you for taking the time to read this!

P.S.: My school doesn’t do class ranks, GPAs, nor do they offer AP and IB classes, or college-level classes.

P.S. 2: Please, feel free to correct any mistakes I made!

2

Most colleges with large numbers of applicants have Admissions Officers that are assigned to certain states (in the United States) and regions or countries in the world (South America, China, UK etc.) It is their job to learn more about the grading policies and school systems of their assigned region, and they do this through high school visits, the school profile (which your counselor’ll likely have to submit as part of their letter of recommendation) etc.