Micky Id love to be able to explain! Im still learning myself.
I'll have a shot though.
1stly this description of TOE will help.
TOE
Look down at your feet and turn them inward so your toes are closer together than your heels -- this is called "toe-in".
Now make your toes further apart than your heels -- this is called "toe-out".
In wheel alignment, "toe" is much the same.
Positive toe (or toe-in) describes that the forward edges of the front wheels are closer together than the rearward edges when the wheels are viewed from above the vehicle.
Similarly, negative toe (or toe-out) has the forward edges further apart than the rearward edges.
In effect the Front Toe in my own set up is +0degree and 1min each side.
Giveing a Total Toe of +0 degrees and 2mins Total Toe.......
Very close to being straight.
The reason for the Toe Out on the rear is to remove understeer from the car.
(1) [ ] (2) (5) [ ] (6)
(3) \ / (4) (7) / \ (8)
^^Exagerated examples
1-2-3-4 = Current Setup. 5-6-7-8 normal setup.
Using 1-2-3-4. When turning right (2) & (4) will be loaded with weight from the turn. Weight will ease off (1) and (3).
In effect what is happening is by running -Toe(Toe Out) on the rear of the car, turn in is quickened and understeer is drasticaly cut, as (4) assists in the turn rather than forceing understeer to occur.
With settings in 5-6-7-8 understeer would be promoted in the same right turn (8) being loaded causeing forces towards(5) in turn needing further steering input.
I hope this helps maybee not the most straight forward way of explaining, but the best I can think of.