Library
A library is a functionality grouped and packaged together. A library performs specific, well-defined operations. A library is just a collection of class definitions. The reason is it simply code reuse, in other words, gets the code that has already been written by other developers.
Framework
A framework on the other hand more complex. It defines a skeleton where the application defines its own features to fill out the skeleton.
Springboot/Rails are popular framework that deals with complexity of handling http request response cycle.
Springboot - makes it easy to create stand-alone, production-grade Spring based Applications.
It is an opinionated framework.
Most Spring Boot applications need minimal Spring configuration.
Rails - is a web application development framework written in the Ruby programming language.
It is designed to make programming web applications easier by making assumptions about what every developer needs to get started.
It allows you to write less
code while accomplishing more than many other languages and frameworks.
React on the other hand is a popular UI library not a framework.
A framework can contain libraries. A framework will usually include many libraries to make your work easier.
Thank you folks.