A Front view displays the model from the front:

• the xz plane is parallel to your screen.
• x is positive from left to right (horizontally).
• z is positive from bottom to top (vertically).
• y is positive away from you, perpendicular to the screen.

While, for a Back view:

• x is positive from right to left (horizontally).
• y is positive towards you, perpendicular to the screen.