As the project has more and more functions, the amount of code will also increase, and later maintenance will become more difficult. At this time, modular specifications will be considered for management in terms of JS. This video covers: understanding modularity, why modularization is needed, the advantages and disadvantages of modularization, and modularization specifications. And will lead everyone to learn commonjs, AMD, ES6, and CMD specifications that are very popular in development. It is recommended that students learn project construction after learning the modular specifications to better equip themselves with skills.