Android developers(mainly beginners) have been confused regarding Internal & External storage terminology. There are lot of questions on Stackoverflow regarding the same. This is mainly because of the fact that terminology according to Google/official Android documentation is quite different to that of normal Android OS user. Hence I thought documenting this would help.

What we think - User’s Terminology (UT)

Internal storage(UT)| External storage(UT)| —— | —— | phone’s inbuilt internal memory| removable Secure Digital(SD) card or micro SD storage|Example: Nexus 6P’s 32 GB internal memory.|Example: storage space in removable SD cards provided by vendors like samsung, sandisk, strontium, transcend and others|

But, According to Android Documentation/Guide - Google’s Terminology (GT)

Internal storage(GT):

By default, files saved to the internal storage are private to your application and other applications cannot access them (nor can the user).

External storage(GT):

This can be a removable storage media (such as an SD card) or an internal (non-removable) storage.

External Storage(GT) can be categorized into two types:

| Primary External Storage | Secondary External Storage or Removable storage(GT)| | —— | —— | | This is same as phone’s inbuilt internal memory (or) Internal storage(UT)| This is same as removable micro SD card storage (or) External storage(UT)| Example: Nexus 6P’s 32 GB internal memory.|Example: storage space in removable SD cards provided by vendors like samsung, sandisk, strontium, transcend and others| This type of storage can be accessed on windows PC by connecting your phone to PC via USB cable and selecting Camera(PTP) in the USB options notification.|This type of storage can be accessed on windows PC by connecting your phone to PC via USB cable and selecting File transfer in the USB options notification.|

In a nutshell,

External Storage(GT) = Internal Storage(UT) and External Storage(UT)

Removable Storage(GT) = External Storage(UT)

Internal Storage(GT) doesn’t have a term in UT.

Let me explain clearly,

Internal Storage(GT): By default, files saved to the internal storage are private to your application and other applications cannot access them. Your app user also can’t access them using file manager; even after enabling “show hidden files” option in file manager. To access files in Internal Storage(GT), you have to root your Android phone. Moreover, when the user uninstalls your application, these files are removed/deleted.

So Internal Storage(GT) is NOT what we think as Nexus 6P’s 32/64 GB internal memory

Generally, Internal Storage(GT) location would be: /data/data/your.application.package.appname/someDirectory/

External Storage(GT):

Every Android-compatible device supports a shared “external storage” that you can use to save files. Files saved to the external storage are world-readable and can be modified by the user when they enable USB mass storage to transfer files on a computer.