Is "Disabling" apps with Android 4 similar to "Freezing" in Titanium backup? I just saw that I can "disable" an app in the app editing menu on my new HTC Droid DNA (stock Android 4.1 w/Sense).

The main effect I can see is that the app disappears from app drawer.

How is this "disabling" different from Titanium Backup's "freezing"? (as far as full effects)
Yes, they achieve the same thing. Not only the app would not be available in the app drawer but the app cannot be launched using am start too. The only difference is that default mechanism allows you to disable specific pre-installed apps while Titanium Backup would allow you to disable any app. 

For Android version like 4.2.1, when you disable a pre-installed app from Android "Settings", this line would show up in /data/system/users/0/package-restrictions.xml:

&lt;pkg name="PKG_NAME" enabled="3" /&gt;


For Android 4.4 or 5.x, it would be:

&lt;pkg name="PKG_NAME" enabled="3" enabledCaller="com.android.settings" /&gt;


where PKG_NAME &rarr; package name of an app, such as for Calculator it is com.android.calculator2.

However, when you disable aka freeze an app using Titanium Backup, the enabledCaller gets the value shell:0, i.e.:

&lt;pkg name="PKG_NAME" enabled="3" enabledCaller="shell:0" /&gt;



In both the cases, if the app is a pre-installed app then it would only show "Enable" option under Settings &rarr; Apps &rarr; your_app.
If it is a user installed app then Android would not show "Enable" option but the app would still be labelled "Disabled".

(Click image to enlarge)






pm is different

pm disable PKG_NAME also disables an app but the app then wouldn't be visible even under Settings &rarr; Apps.

Also, when you disable an app using pm disable a different value for enabled is recorded.

For Android 4.2.1:

&lt;pkg name="PKG_NAME" enabled="2" /&gt;


For Android 4.4 and 5.x:

&lt;pkg name="PKG_NAME" enabled="2" enabledCaller="shell:0" /&gt;


You can disable any app using pm provided that you've root access.