Dageš, a point standing in the middle of a consonant, denotes, 

(a) the strengthening of a consonant (Dageš forte), e.g. קִטֵּל‎ qiṭṭēl ; or

(b) the harder pronunciation of the letters בְּגַדְכְּפַת‎ (Dageš lene).

The root דגשׁ‎ in Syriac means to pierce through, to bore through (with sharp iron); hence the name Dageš is commonly explained, solely with reference to its form, by puncture, point. But the names of all similar signs are derived rather from their grammatical significance. Accordingly דגשׁ‎ may in the Masora have the sense: acuere (literam), i.e. to sharpen a letter, as well as to harden it, i.e. to pronounce it as hard and without aspiration. דָּגֵשׁ‎ acuens (literam) would then be a sign of sharpening and hardening (like Mappîq מַפִּיק‎ proferens, as signum prolationis), for which purposes a prick of the pen, or puncture, was selected. The opposite of Dageš is רָפֶה‎ soft,