Chemistry is often called the 'Central Science', in recognition of its crucial position in the panoply of Science. From years of decades, the world of chemists is trying to make the nature at a pure molecular level. This consideration brings out the chemists to a new world, a new era of chemistry known to us as supramolecular chemistry which initiates the many folds understanding of lock-key enzyme interactions as well as host-guest interactions. As is the name supramolecular chemistry, it deals with the synthesis of macrocycles like crown ethers, cryptands, calix[n]arenes, cyclodextrins, etc. which provides platform for host-guest interactions, molecular self-assembly, folding, molecular identification, mechanically interlocked molecular structures and dynamic covalent chemistry. Calixarenes came as the third generation of supramolecular host compounds. Now-a-days, numerous synthetic supramolecules are known and macrocycles having the cavities can completely surround the guest molecules and modified compounds are expected to give novel chemical, physical and biological properties.