Hello guys,

I am making a project with Eclipse, and I am going to insert a fault trajectory. But there's a terminology "face" which I do not have any idea what it is since I am not a geologist. It is an option list, with the options of "X", "Y", "Z", "-X", "-Y", "-Z". I am still wondering, what is actually the definition of "face" here?

Any help would be appreciated. Thanks in advance!