I am looking for a software that would help me in improving my positional chess understanding. Is there any such software or website?
Perhaps an engine something like Chess Position Trainer, depending upon your requirements (and system).
There is some potential for an unexpected learning curve, at least within version 5.04.
That being said, it is noted as working in both Windows & Linux.
Komodo 8 also gets some recommendation.
Basic Positional Ideas "...is a supplementary program [that] can only be run if [sic] Fritz 8...". The description indicates that the program is for learning "...[how] to achieve the desired position on your board...".
The use of Fritz indicates that it should run on Windows, but that you might need Wine in order to run it within a Linux environment.