What Came Before: the Android Support Library

Many of the capabilities described here as being part of Jetpack have existed for a while, in some cases for many years.

The biggest change with Jetpack — besides the branding — is the set of libraries that we use. The Jetpack libraries are all “AndroidX” libraries, where we will be referring to libraries and Java packages that have androidx in their names.

Prior to Jetpack, we had a set of libraries that evolved over the years, with a variety of naming schemes for libraries and Java packages. Much of what is in the Jetpack originated in what we called the Android Support Library. Some came from the Architecture Components, which was another family of libraries.

Since Google debuted Jetpack in May 2018, anything written prior to that would be referring to these older library collections. Most of what was in those libraries has been replaced by AndroidX equivalents, though not everything. This will cause some amount of confusion, particularly since a single Android project cannot easily combine the older libraries (Support Library and Architecture Components) and the AndroidX libraries.

As a result, particularly as you learn Android app development, it will help if you know the dates for your educational materials and online resources. Whenever you see a date prior to May 2018 — and even for some stuff after that date — just bear in mind that you may need to convert some older library and Java package names into their AndroidX equivalents.