Energy resistance was a Force power used by many Jedi, especially those fighting during the Jedi Civil War. Its main effect was to create a barrier of energy-absorbent force around the user, reducing the damage taken from energy weapons like blasters. Darth Revan may have known this power.
As the user became more powerful through the Force, they were able to learn and make use of advanced forms of energy resistance. This power was mainly used by light side Jedi.
Another, more advanced version of energy resistance, allowed the Force user to not only protect themselves but their allies as well. It granted immunity to poisons and disease, and absorbed a slightly higher amount of damage than energy resistance.
The technique was similar in usage and capabilties to that of Tutaminis and Force deflection.