How do I know if I'm using an infopath form or a share point list form in SP2010?

I am eager to learn more about Infopath. How do we know if we use a custom infopath form or a share point list form. Is it possible to find the one we use to create items on the library list? SP2010 environment. Subsite, we had a library, lists, and a reusable workflow associated with the site. I want to know if there are or not custom infopaths on my subsite. please suggest me how to get it.