International Online Quran Acadey:-

Tajweed means to pronounce or recite every letter correctly, i.e. from its proper origin of pronunciation coupled with its stipulated attributes such as prolongation (Madd), merging (Idgham), conversion (Iqlab), and pauses (Waqaf) etc. Tajweed and its application can only be learned with a qualified Quran teacher. The rules themselves can be studied independently, but the correct application and proper pronunciation of the alphabets of Qura'an can only be done by reading to, listening to, reciting to, and being corrected by a qualified teacher of the Qur’an.