The primary objective of this paper is to provide an overview of existing methods Text-To-Speech synthesis techniques. Text to speech synthesis can be broadly categorized into three categories, formant Based, Concatenative based and Articulatory. Formant based speech synthesis relies on different techniques such as cascade, parallel, klatt and PARCAS Model etc. Concatenative speech synthesis can be broadly categorized into three categories, Diphones Based, Corpus based and Hybrid whereas Articulatory synthesis involves Vocal Tract Models, Acoustic Models, Glottis Models , Noise Source Models . In this paper, all text to speech synthesis methods are explained with their pros and cones.