On this website, I use guitar tablature and fretboard diagram to explain how to play the guitar.
Guitar tab looks like this.Linear-Guitar-Scale-Part-2
There are 6 lines and numbers. Each line represents each string, the top one is 1st string and the bottom one represents 6th string.
The numbers represent where you need to hold the guitar, we call these numbers as 1st fret, 2nd fret, 3rd fret and so on.
For instance, if you see number 1 on the top line, that means to play 1st fret of 1st string.
Fretboard diagram looks like this.
In this case it's the same that horizontal 6 lines represent 6 strings of the guitar, top is 1st sting and bottom is 6th string.
Vertical lines represent the fret, and circle is where we want to put our finger on.
Left side is where the guitar head locates and right side is where guitar's body is.
You can think this is a simplified version of fingerboard as you can see below.
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