A framework provides a skeleton of rules, pre-arranged code, directory structure, and other structures in which the front-end developer can build their application. Using frameworks can make building complex applications more efficient. Examples of frameworks are Vue.js and AngularJS.
Some frameworks are ‘opinionated’, in which you really have to follow the rules of that specific framework. Others give you more freedom to do it in your own way.
Frameworks differ from libaries. Both are used to make development more efficient. But where a framework provides a skeleton wherein the developer needs to develop, a library only provides the tools the developer can integrate in their own application setup. In other words, a framework is more opinionated than a library.