what does the b mean when it's 1-b3-b5 (c dim chord)

So I understand the first, third, and fifth numbers when it says 1-3-5 of a chord, It's just the first, third, and fifth notes of the key. But now don't understand what the B means because I am trying to figure out and use these chords.

b=flat Lower the note one fret
C chord = C E G
C minor= C Eb G
C Diminished = C Eb Gb

not necessarily one fret, but a semitone lower

I'm sorry dude, yeah it's a semitone or half step. I guess I've got a one track mind and keep guitars on the brain.

Is'nt one fret, a semitone, and a half step all the same thing?

i thought it was.

It is but semitones and half steps apply to all instruments but one fret only applies to fretted instruments.

It only applies to instruments which are fretted in intervals of semitones! ;)

I'll risk sounding dumb but which instruments are fretted in whole steps/tones????
EDIT: I found this..
Many instruments' frets are not spaced according to the semitones of equal temperament, including the Appalachian dulcimer (with frets in a diatonic scale), the Turkish Saz (with frets spaced according to the Makam system of Turkish folk music), the Arabic Buzuq (with frets spaced according to the Arabic maqam system), and the Persian setar and tar (with frets spaced according to the Persian Dastgah system), and the Turkish tanbur (with as many as 5 frets per semitone, to cover all of the commas of the Turkish Makam system).
You learn something new everyday!!

Ok now that makes sense. A guitar has 12 semitones or half steps or frets between an octave. Truthfully, I wasn't sure! Just as I was unsure about "truthfully". Is it one L or two Ls? (I had to use spellcheck in Outlook!

And that's exactly what makes me crazy about theory! It's a language just as the English is a language and there are all kinds of rules. I could have typed truthfuly with one l and you still would have known what I meant. Just as slang is technically wrong but we use it because it allows us to be different and creative. As long as the reader/listener is interested/understands, it's all good!

There are even guitars with quartertones and stuff!

That's cool man. I've never seen a fretboard like the bottom picture. In my post above..the Turkish tanbur (with as many as 5 frets per semitone),5 FRETS TO COVER A SEMITONE!!!!!!!!

If I counted correctly the guitar on top has 55 frets :O

That 8 string is SO metal

wow!! 55. Don't you need tiny fingers?

Cool! Yeah, Uli Roth invented the Sky Guitar which has like 42 frets. Some are whole steps and some are half.

Uli seems kinda off in that video

I agree. I just picked the first one off of youtube without listening to it. I just wanted to show the guitar. He's kinda old too. Remember he pioneered the neo-classical style that influenced Ynwie and all the others.

@macandkanda...........cool video