Reading up on air filters

What is a very strange thing, and has had me quite curious, is the basic fact that every damn time I am searching online to see what the best possible air filters are, I am constantly seeing that HEPA brand is the best out there. What I would love to know is why HEPA air filters are the best? I keep seeing this everywhere I go, although I can not find any answers as to why HEPA air filters are the best for the situation. I’ve noticed discussions about HEPA air filters for all kinds of things! However, when I was learning about the HEPA filters for heating and cooling systems, I was starting to get a rough idea of why people rave about these things. It seems like HEPA air filters have a longer lasting life compared to other air filters for heating and a/c on the market today. When I say longer lasting life, I am referring to the amount of time they can remain in the central heating and method before having to be switched out after a few months. HEPA air filters are a little more extravagant than generic air filters or even other major name brand air filters, depending on where you go to buy them. I do know what I have read previously, however the only thing that keeps bothering me is that I can’t find anything else documented other than they last a little longer than other air filters, but something is a bit odd to me there. I have a feeling that I am going to just go out and buy some HEPA air filters to test in my very own Heating, Ventilation, and A/C system.
multi split air conditioning