Would someone explain what "up sampling" means and how it can affect the sound?

I am looking at buying a DAC and after reading a few articles, there seems to be a question that comes to mind: what is up sampling, and does it affect the sound ? Some audio companies have up sampling in their DAC and some do not.
I just want to make an educated decision about what DAC I purchase that, hopefully, will not be obsolete in a few years.
Thank you for all your comments and answers.


Showing 1 response by tls49

Well, I agree with chayro’s statement and disagree with gdhal's statements, "Seems to me it would be best to make an educated decision based on all possible information available. That would include specifications, your own subjective listening, opinions of reviewers, value of the component, etc." You don't listen to specifications and just because a reviewer raves over a unit doesn't mean you will like it. Bottom line is you buy what your ears like. Too many people buy for the wrong reason, and all you need to do is trust your ears.