Shoplifting refers to stealing items from a shop or store and not paying for them. For example, Ram and Shyam go to a provision store to steal chocolates and run away without paying for them.
In India, shoplifting is governed by the same laws as the general law on theft. Read more here to know what theft is and what the punishment is. If you have experienced shoplifting, read here to understand the steps/options you can take to complain.