What Ramadan is and why we fast
Allah says: ‘The month of Ramadan in which the Quran was revealed as guidance for mankind’ (Quran 2:185). The verse that makes fasting obligatory says it was prescribed so that believers may attain taqwa, awareness of Allah (Quran 2:183).
Fasting Ramadan is the fourth pillar of Islam. It is required of every Muslim who is adult, sane and able, and who is not travelling. Those who are ill, travelling, pregnant, nursing or in menstruation have allowances and make up the days later. See the articles on who is exempt and on making up missed fasts.