, then only the purely transparent pixels in your texture will be discarded, or:
. This will enable blending of semi-transparent pixels. This is much more advanced, and usually you don't need it. Also different draw orders are giving different results... for example if I draw A over B, the resulting color is different than when I draw B over A.
Finally, please google more, and the docs are your friend:glEnable();Alpha TestBlending
Also, mind that you can "configure" both the Alpha Test and Blending with
glAlphaFunc is pretty simple, I'd suggest you to "start" with this, since you don't even need something else in most cases,
and you only need blending if you want to do stuff with transparency. Mind that it's much more complicated.