Small signs with an essential job
Harakat (حَرَكَات) are vowel marks placed above or below Arabic letters. The singular is Harakah (حَرَكَة). They guide the reader to produce a short vowel immediately after a consonant.
The three basic Harakat are Fatha ـَ, Kasra ـِ, and Damma ـُ. Urdu-speaking learners often call them Zabar, Zer and Pesh.
Arabic is built mainly around consonants. The Harakah does not replace the consonant; it tells you how to release that consonant into a short vowel sound.