There are 6 lines representing the 6 strings on the guitar.
The lowest line on the diagram is the thickest string. (this may seem a bit odd to some people)
The numbers represent the frets that are being used on each string
As an example, here is a regular E chord
0 = open (or unfretted) string
1 = 1st fret
2 = 2nd fret etc....
X = deadened string. This is done by very slightly angling a finger or thumb to lightly touch the string & so prevent it from sounding.
(3) 4 = hammer-on, pull-off, bend or slide. play fret in bracket & quickly move to the next fret number.
More explanations coming soon, if I can think of any. Apologies to anyone who actually reads tablature.
Any questions please message Eric