For the extended version:
While that's the common understanding, it must be stated that they are simply saying that 100 level subjects cover more basic and foundational concepts, 200 level builds upon 100 level subjects, and 300 builds on that, and so forth.
The problem with calling them 1st/2nd/3rd year is that people confuse that to mean they cannot take 200 (or 300) level units in first year. As long as you can satisfy the pre-requisites for a course, that is what you need to have completed/studied before taking the course, you are able to take it.