Difference between layout and layout v17 in android studio

Question

I'm very very new to Android programming and recently I've been trying out with android studio 2.1

There's 2 layout in my activity main which is layout and another one is v17

could anyone tell me what's the difference between these two?

Sorry if it's a stupid question :/

thanks!

Answer 1

Android knows quite a few resource types, for example: drawable, values, layout

In Android Studio you see them as subnodes under res. If you find a node containing a minus sign (for example values-w820dp), this denotes a qualified resource.

Qualifiers control when or where a resource is used. Most often qualifiers are used to specify device characteristics, for example its display having a minimung available screen width of 820 density indipendent pixels.

Or, as in your case, a minimum api level. So that resource is used only on devices with an Android version greater or equal to 17 (Android 4.2, 4.2.2).

It is very important to keep in mind that for each qualified resource there must be a fallback resource which is used in the qualifier is not met.