General hex editing question... why are some strings searchable, and other's not?

[behealed]

This is a very basic question but I'm new to hex editing. I have a phoenix ROM file that I'm loading up in the Phoenix rom editor and it shows me a long list of strings of text, such as "PhoenixBIOS Setup Utility". But when I load the same ROM file into a simple hex editor such as HxD, or even a fancy dissassembler such as IDA, I see no such string plainly visible (actually, I don't see any such string at all, period). So this is probably an extremely simply question that only n00bs like me wouldn't already know the answer to, but how is the Phoenix Editor getting so many text strings, and these other programs don't?

Reason I ask is because I also have a VGA.ROM file to go along with my bios rom. And I can edit the bios rom in the phoenix rom editor, but the VGA.ROM that I have obviously doesn't load into that editor. So I'm trying to find strings in the VGA.ROM file, such as the name or hardware id or manufacturer name or basically any string at all. I feel like, if I could understand how phoenix editor is finding all those strings in the bios file, then maybe I could better understand how I could do the same thing to find strings in the VGA.ROM file, if that makes sense. Hopefully the method for finding strings would be the same for both files. That's how my n00b brain thinks anyway.