Vectors are represented by a string of the form:
(X Coordinate, Y Coordinate, Z Coordinate)
When entering vectors into text boxes, this is the expected form. Here's an example:
The axes can be considered as being lined up as follows: If you are standing in a room, the Y-axis is aligned with your spine. If you hold out your right arm so it's pointing straight out to your right, that is the X-axis. And your gaze straight ahead is the Z-axis.