Two stylesheets added to the same page, how does it work?

[Dexter1996777]

Hello everyone!
In Chapter 14, we've got two stylesheets linked to the html code. But at the same time, these css codes have the rules that are meant to stylize elements that are not mentioned in the html. Could you explain me please, how it works? Does it mean that these ccs stylize the elements only included by the html code and the rest is ignored?

One more question: the html does not have "type="text/css"", but the style works perfectly. So we do not have to always use "type="text/css"" to sylize an html?

https://github.com/bethrobson/Head-First-HTML/blob/master/chapter14/starbuzz/styledform.html