The question of whether the universe is infinite or not is still an open topic of scientific investigation. The current understanding among cosmologists is that the universe could have one of three possible geometries: flat, positively curved (finite), or negatively curved (infinite).
The idea of the universe being infinite or finite is related to the concept of the curvature of space. In a flat universe, which is the most widely accepted model based on observations, the universe would extend infinitely in all directions. In this case, the universe would be infinite, and it would not have an "edge" or a boundary.
However, it is important to note that our observations are limited to the observable universe, which is the portion of the universe we can see and study due to the finite speed of light and the age of the universe. Beyond our observable universe, there may be regions that are currently beyond our reach and remain unobservable.
So, the term "infinite" is used in the context of our current knowledge, implying that the universe could extend indefinitely beyond our observable limits. Whether the universe is truly infinite or has a finite size beyond our observational reach is a question that requires further scientific investigation and data. Future observations and theoretical advancements may provide more insights into the true nature and size of the universe.