What is Ionic and where does it fit?

Ionic is an HTML5 mobile app development framework targeted at building hybrid mobile apps. Hybrid apps are small websites running in a browser shell in an app that has access to the native platform layer. Hybrid apps have many benefits over pure native apps, specifically in terms of platform support, speed of development, and access to 3rd party code.

Think of Ionic as the front-end UI framework that handles all of the looks. It feels and UI interactions your app needs to be compelling. Kind of like "Bootstrap for Native", but with support for a broad range of common native mobile components, slick animations, and beautiful design.

Unlike a responsive framework, Ionic comes with very native-styled mobile UI elements and layouts. You would get with a native SDK on iOS or Android but didn’t exist before on the web. Ionic also gives you some opinion. It is a powerful way to build mobile applications that eclipse existing HTML5 development frameworks.

Since it is an HTML5 framework, it needs a native wrapper like Cordova or PhoneGap to run as a native app. We strongly recommend using Cordova proper for your apps, and the Ionic tools will use Cordova underneath.

Can we use jQuery in ionic?

But that is not the way to go and I don't see a reason why there's a need for jQuery in ionic projects.

Ionic Frameworks comes with lots of UI goodies that you can make use of in your project. The best part is you can control the UI part completely from CSS. Even you can use the CSS3 animations to implement any widget specific animation.

Framework Compatibility

 It can be used in most frontend frameworks with success, including React and Vue, though some frameworks need a shim for full Web Component support.

Cross-platform

Build and deploy apps that work across multiple platforms, such as native iOS, Android, desktop, and the web as a Progressive Web App - all with one codebase. Write once, run anywhere.

Web Standards-based

Ionic Framework is built on top of reliable, standardized web technologies: HTML, CSS, and JavaScript using modern Web APIs such as Custom Elements and Shadow DOM. Because of this, the components have a stable API and aren't at the whim of a single platform vendor.

Beautiful Design

Clean, simple, and functional. Ionic Framework is designed to work and display beautifully out-of-the-box across all platforms. Start with pre-designed components, typography, interactive paradigms, and a gorgeous (yet extensible) base theme.

Simplicity

Ionic Framework is built with simplicity in mind so that creating apps is enjoyable, easy to learn, and accessible to just about anyone with web development skills.

Structure

https://ionicframework.com/docs/layout/structure