Porous liquids (PLs) are an emerging field of advanced func­tional materials with tremendous applications. In this article, we aim to introduce porous liquids. We know that liquids are in a condensed state, which is the second state of matter. It can flow, and therefore, the molecules are constantly in ran­dom motion. Permanent porosity (micropores) can be devel­oped within them through careful tailoring involving remark­able synthetic and supramolecular chemistries. The resultant PLs have the combined features of solids' porosity and liq­uids' fluidity. The invention of PLs is an important scientific milestone that opened up an entirely new approach to indus­trial separations processes. The present article enumerates the concept of PL, the different types of PLs and their appli­cations. The article finally discusses the challenges and future prospectus of porous liquids.