Difference bewteen B-777 LR and ER

[fire667]

I am interested to know the basic difference between the two versions of B-777 i-e LR *( longer range ) and ER ( extended range ) I assume it is the range the aircraft can go so if I could have exact range of the two aircraft s .
Also I am would love to know if there is any site which explain there system in detail .

[Jet II]

Try going to Boeing - they give the technical differences between the two models.