Appium is a Test Automation Framework which is used for automating mobile applications(Mobile Apps).
Appium supports Android , IOS mobile apps and Windows PC Desktop apps.We can automate Native , Hybrid and Mobile web apps using appium.
Native app is an app which belongs or developed for respective OS(Android,IOS and Windows etc) with those SDKs.This Native app can't be installed in cross platform such as Android App can't install in IOS.
Mobile web apps are the apps accessed using a mobile browser, For an example , Accessing facebook via chrome browser.
Appium supports Safari on iOS and Chrome or the any built-in 'Browser' app on Android.
Hybrid apps have a wrapper around a "WebView" which is developed using web technologies such as HTML, CSS and JavaScript etc or other languages like Dart , that are then converted into a native app.
The process of creating an app with one technology and then converted into a respective native app is called hybrid app process.
Framework Tools like React Native , Flutter, Apache Cordova and Phonegap are used to build hybrid apps using web technologies or other technologies that are then converted into a native app.
A program language that provides a set of ready made methods or functions which is used to do specific actions is known as framework.