Grading systems differ across countries. Let's look at the most common systems used in Germany, USA, and Slovakia.
Germany uses a system from 1 (best) to 6 (worst). It's similar to the Czech system but has one more grade level.
The USA uses the A, B, C, D, F system, where A is the best and F means failure. This system is also common at Czech universities.
Slovakia uses the same system as Czech Republic - grades from 1 to 5, where 1 is excellent and 5 is insufficient.