I do understand some basic theory but...(this may seem silly) (here goes..) When you play the same note in different positions they sound the same i.e a on 5th fret 6th string and open 5th string. Same note same sound.. 5th string 12 fret-different sound-one octave higher and sounds it. 4th string 7th fret sounds different to open a but exactly same as 12 fret 5th string. 1st string 17th fret is highest a. Does each note reoccur one octave higher untill this high a from lowest a?? But some a's in different places are exacly the same pitch? AND if you play say a major scale from 1st position (5th 6th string fret root) then 2nd pos (7th fret 4th string) is it same but one octave higher?
Well, it has to do with Strings. Open and Thinner strings will sound different then the thick (Covred, for lack of a better term) Strings, as well as general tension.
Some of the same note are the same note, some are the same note just an octave higher. Or in other, twice as high. It's the same note, and still sounds the same, but is just an octave higher.

EDIT: Well it doesn't sound the SAME, but you can definitely tell it's the same note.
I do understand some basic theory but...(this may seem silly) (here goes..) When you play the same note in different positions they sound the same i.e a on 5th fret 6th string and open 5th string. Same note same sound.. 5th string 12 fret-different sound-one octave higher and sounds it. 4th string 7th fret sounds different to open a but exactly same as 12 fret 5th string. 1st string 17th fret is highest a. Does each note reoccur one octave higher untill this high a from lowest a?? But some a's in different places are exacly the same pitch? AND if you play say a major scale from 1st position (5th 6th string fret root) then 2nd pos (7th fret 4th string) is it same but one octave higher?

Right, let's take an E on the 2nd fret of the D string.

This will be one octave higher than the open low E.

If you fret the 12th fret of the E string, also one octave higher than the open E string, it will sound the same as the 2nd fret of the D string.

Basically, a 24 fret guitar has:

-12 completely different notes; this is the way Western instruments 'work'.

They are C, C#, D, D#, E, F, F#, G, G#, A, A# and B

-49 different notes in the sence that they are made up from the 12 different notes, although some are an octave higher than others.

-150 notes; there will be 25 notes per string, times 6 strings, so 150 notes

That means that 150-49=101 notes can be found on other places on the neck, at the same pitch.

Take the note E:

It can be found at:

-the open low E
-the 12th fret, low E
-the 24th fret, low E
-the 7th fret, A string
-the 19th fret, A string
-the 2nd fret, D string
-the 14th fret, D string
-the 9th fret, G string
-the 21st fret, G string
-the 5th fret, B string
-the 17th fret, B string
-the open high E
-the 12th fret, high E
-the 24th fret high E

They're all the note E, yet some are the same pitch.

On the entire guitar, there are only five different octaves of E (or E notes at a different pitch):

-open low E
-12 fret low E
-24 fret low E
-12 fret high E
-24 fret high E

Any other of the afore mentioned E's are the same pitch as those 5 notes.

Take an A at the 5th fret of the low E, for instance. This is the same note, at the same pitch as the open A string.

Some do sound a bit different though, which has to do with:

-the fact that open strings sound different from closed strings; the 5th fret of the E string doesn't sound exactly like the open A

-the difference in tone between individual strings; for instance, a wound string sounds different from a non-wound string

-intonation; sometimes the intonation is off, meaning that eventhough you fret the right position, you don't hear the right note

If you have a 24 fret guitar, the 24th fret on the low E is the same note and pitch as the open high E, yet it sounds pretty different.