What is Reactjs?
But from my point of view reactjs is more than just a library because it provides so much flexibility for building the user interface and user experience.
Reactjs is basically working on the concepts of Components.
Where Components could be anything like navbar , sidebar, header, etc.
In the world of Reactjs you would hear Reusable components frequently.
###But what does Reusable components means?
Create once and use anywhere & any number of times
That means you can create one component for example navbar and use anywhere and any number of times in your project.
Why it is so popular?
According to Stackoverflow survey 2020 Reactjs is 2nd most loved and 1st most wanted library and framework.
Also, reactjs has a great community where you can find all your answers regarding specific topics.
There are plenty of resources available to learn recatjs. I recommend you should first start with official website of reactjs. they have very good documentation with a great explanation.
Comment down if you have any questions. I will be happy to solve your queries.