can anyone tell me what exactely this means? "NATO STANAG mounting"
i know what a weaver mounting system is and i know what a picatinny mount is.

It's basically a slot that runs the length of the mount and the optic is held in place with two screws.  It's similar to an ACOG mount.

is there a preference to the type of mounting for scopes?
i dont care for the weaver system.
is one better than the other?

Nato STANAG is the standardization agreement for NATO countries. How if applies to the mounts, is there are specific deminsions for mounting positions, diameters, etc.

NATO STANAG

When it comes to the mounts I've seen, the scopes that are STANAG compatible have two screw holes in the bottom instead of rings. As stated above, the scope screws to the mount.

The picatinny (modified Weaver) has become the standard. IIRC, Weaver specifies a recoil lug on the bottom of the ring to keep it from shifting on the base.

The benefit of the picatinny rail is it allows for better odds of retaining zero with QD rings. There are a few different options, such as turn in bases like the Leupold STD, and claw mounts. Claw mounts usually are found on european gunsand have hooks that engage a base.

As far as which is better, it depends on that application. I used a Leupold STD base on a bolt gun that was better than a picatinny rail and ARMS rings for me.  I never had a shift of zero and the rifle took some moderate abuse.