The musical term d.s. means "repeat from the mark" and is the abbreviation of Da Segno.
When you see the D.S. mark in the music score, you should start playing from where the D.S. mark is sometimes used until the end of the music. This mark is usually written at the end of a paragraph. Or mark the text written in the staff. The previous marks are usually written at the top of the staff.
Commonly used musical terms
Diminuendo/dim
Piano Pianissmo/ppp
Very weak ( Pianissmo/pp)
Piano/p
Mezzo Piano/mp
Crescendo/cresc
Mezzo Forte/mf
Forte Fortissimo/fff