Tabs, or tablature, is a method of recording musical text intended for performance on stringed fret instruments (all types of guitars, permissible for balalaikas, lutes, etc.). The tablatures inherited the notation of durations from the standard notation system, but otherwise there are significant differences.
The standard staff recording system has five rulers. In tablature, the number of rulers is equal to the number of strings on the instrument: four-string bass - four rulers, seven-string guitar - seven. Accordingly, each ruler corresponds to a string, from the first (the top on the "staff", the thinnest on the instrument) to the last (fourth, sixth, seventh, twelfth, etc.). In other words, if the second ruler from the top is marked on the tablature, then you need to hold down the second string.
The numbers on the ruler indicate the fret number to be clamped. The number 0 means that the sound is being played on an open string (you do not need to clamp anything). For example, if the number 2 is marked on the second ruler, hold down the second string at the second fret.
To indicate chords on tablatures, several numbers are located one below the other. Therefore, you need to simultaneously clamp the indicated strings on the indicated frets.
Durations in the tablature notation system are indicated in the same way as in standard notation: a whole note is an open circle, a half is an open circle with a calm (vertical stick), a quarter is a shaded circle with a calm, etc. The duration of the pauses is indicated by the same signs.