Data is your user apps (installed from Google Play Store, or with an *.apk) and its app data. It is stored on /data.
Your user apps is stored on /data/app
.
Your apps' data is stored on /data/data
.
NOTE: You must be rooted to see the contents on /data/ ...
On the other hand, Internal Storage
is actually the storage where your other data are saved, such as music, photos, videos, other app data, downloads, etc., and is usually stored on /storage
or /sdcard
.
NOTE: /sdcard
is different from your external SD Card.
Music is saved on /sdcard/Music
.
Photos are saved on /sdcard/DCIM
.
Videos are saved on /sdcard/Videos
.
Other app data are saved on /sdcard/ (App Folder)
.
Other apps choose to store their app data on /sdcard/ ..., such as Minecraft: /sdcard/games
.
Downloads are saved on /sdcard/Downloads
, and can be easily found if you have the Downloads app.
rom flashing - What's the difference between Data and Internal Storage? - Android Enthusiasts Stack Exchange