Polyphenols are chemically defined as compounds characterized by the presence of an aromatic ring bearing one or more hydroxy substituents, encompassing functional derivatives such as esters, methyl ethers, glycosides, and a few. Predominantly, phenolics exhibit two or more hydroxyl groups and represent bioactive compounds found extensively in plants constituting a regular dietary intake for significant populations worldwide. Plant polyphenols generally act as antioxidants highly involved in general defense mechanisms in living organisms, broadly divided into four classes: phenolic acids, flavonoids, stilbenes, and lignans. This comprehensive exploration scrutinizes the intricate world of phenolic compounds found ubiquitously in a few plants. Encompassing simple phenols, phenolic acids, hydroxycinnamic acid derivatives, and flavonoids, these bioactive substances intricately shape the color, flavor and nutritional qualities of both fresh and processed plant foods. Our investigation extends to the general identification and documentation of the reported plant polyphenols in two common fruits, banana and Garcinia, available in North-East India. In this chapter, we embark on an enlightening journey into the world of polyphenols, exploring their pivotal role in food science.