What does the Invalidate Caches/Restart do in Android Studio?

Question

I have seen many answers suggest that one should Invalid Caches/Restart in order to improve the performance of Android Studio, whether it's memory or CPU. It also can be used to set up correct themes. I was wondering what it actually does though, since it seems to be the solution to so many problems.

Answer 1

Android Studio makes a lot of files as caches and does not delete them. This can cause trouble when there is a need to make new files, so clearing caches will clear the old cache and make Android Studio faster.

Answer 2

Invalidate Cache clears project structure related information (only) cached by Android studio. Please note that this cache is different from "Build Cache" and "Gradle cache" briefly explained below.

Build Cache - stores certain outputs that the Android plugin for Gradle generates when building your project e.g. unpackaged AARs and pre-dexed remote dependencies. Build cache is enabled by default in recent plugins (2.3.0+).

Build Cache path: C:\Users\[User_Name]\.android\build-cache\gradleVersion

Here version value is driven by value defined in build.gradle file in your project. e.g. classpath "com.android.tools.build:gradle:$gradleVersion" Invalidate Cache has no impact on Build Cache. It can be cleared using "gradlew cleanBuildCache" command instead.

Gradle Cache - maintains Download Dependencies.

Gradle Cache path: C:\Users[user_name]\.gradle\caches\modules-2\files-2.1 [Windows] ~/.gradle/caches/modules-2/files-2.1 [Mac]

Also, as mentioned by @anurag, Clean Project has no relation to Build Cache.

More @ https://developer.android.com/studio/build/build-cache