What exactly is Android Jetpack?
On its official site, it says:
Android Jetpack is a set of libraries, tools and architectural guidance to help make it quick and easy to build great Android apps. It provides common infrastructure code so you can focus on what makes your app unique
Technically, it is the support library, android-ktx and the Android Architecture Components re-branded as a single modular "entity".
This is why all non-Android extension libraries like support, etc. are re-packaged to androidx.**.
Quote from Alan Viverette (from Android Framework Team):
Jetpack is a larger-scoped effort to improve developer experience, but AndroidX forms the technical foundation. From a technical perspective, it's still the same libraries you'd have seen under Support Library and Architecture Components.
As best practices change, you may also see libraries in the androidx.* package that are not included in Jetpack.
See https://developer.android.com/topic/libraries/support-library/refactor for more info.
Basically it is just set of useful things combined and sorted under 4 categories
Foundation
Architecture
Behavior
UI
Some of the core things like AppCompat library, Architecture components, Fragments, Animation and transitions and many more were added now in relative categories and these 5 things were newly added.
Android Ktx
The purpose of Android KTX is to make Android development with Kotlin more concise, pleasant, and idiomatic by leveraging Kotlin language features such as extension functions/properties, lambdas, named parameters, and parameter default values
Navigation
The Navigation Architecture Component simplifies the implementation of navigation in an Android app.This is related to implementing a clear flow in your app. Here in this video you can find a very nice explanation about this topic.
Paging
The Paging Library makes it easier for you to load data gradually and gracefully within your app's RecyclerView. Here is the I/O talk from Yigit Boyar, It's very well explained by him.
Slices
Slices are UI templates that can display rich, dynamic, and interactive content from your app from within the Google Search app and later in other places like the Google Assistant. Slices can help users perform tasks faster by enabling engagement outside of the full screen app experience. You can build Slices as enhancements to App Actions. Learn more from this talk
WorkManager [ I personally recommend you to check this thing out ]
You can gracefully schedule tasks with WorkManager.The WorkManager API makes it easy to specify deferrable, asynchronous tasks and when they should run. These APIs let you create a task and hand it off to WorkManager to run immediately or at an appropriate time. This Video explains it in depth.
I have created a playlist Here. It consists all best videos related to Jetpack, Hope this helps.