What is wrap mode (as seen in 2.6 FBX importer component, on any imported animation) at the bottom.
WrapMode determines how time is treated outside of the time range of an animation clip, i.e., after the animation clip is done playing the first time. Check WrapMode in the scripting reference.
The WrapMode options are:
Default: Reads the repeat mode from the animation curves, which can be set to Loop or PingPong.
Once: When time reaches the end of the animation clip, the clip will automatically stop playing.
Loop: When time reaches the end of the animation clip, time will continue at the beginning.
ClampForever: Plays back the animation. When it reaches the end, it will keep playing the last frame and never stop playing.
PingPong: When time reaches the end of the animation clip, time will ping pong back between beginning and end.
The WrapMode in the animation import settings is new in Unity 2.6 and was introduced to require less scripting setting up how animation clips should wrap. Normally there are some animation clips that should always loop and other animation clips that should never loop, so it's better to specify the WrapMode once in the import settings than to have to specify it in scripting every time an animation is used.
The WrapMode specified for the animation clip will be used for the animation state. However, it's still possible to set the WrapMode of animation states directly in scripting, which will then overwrite the WrapMode that the animation state got from the animation clip.
Wrap mode is how the animation loops: normally it starts from the beginning when finished but you can also set it to pingpong. This first play's forward then and the end play's the animation backwards.
and so forth.
there are more options, check this: link