In the history of aircraft designs, the tail has served a main function other than the various configurations known now which is the stability. The horizontal tail provides longitudinal stability and pitch control and the vertical tail provides a directional stability and yaw control.
The conventional aircraft tail is illustrated in the following Figure. In this configuration the important part is the vertical tail which contributes to lateral stability in term of yawing moment to reach trim for aircraft.
The V-tail was invented and patented in 1930 by Polish engineer Jerzy Rudlicki. In the V-tail configuration it can be seen it has only two fins placed at a dihedral angle from the ground with control surfaces is called Ruddervator as in following figure
The most noticable advantage of a V-tail is the less wetted area which reduces aerodynamic drag compared to a conventional tail type and it reduces tail buffeting from wing wakes. The control surfaces serve both pitch and yaw moments as in following Figure
The v-tail performance has been tested by researchers and the result of the static stability shown that the interactions between wing and V-tail with vortex has influenced the performance of the V-tail. The result is the v tail interactions has more tendency to be longitudinal static stable and less on the lateral static stable as researchers claim.
Most of the high speed jet fighters are recognized by their V-tail design but what is more interesting is the new Boeing UAV which is running some ground tests and it has a V-tail design.