Question

write one similarity and one difference between electrostatic energy and gravity

Answer 1

Similarity : inverse square law for strength of force compared with distance. 

differences : 
gravity just attracts 
electric force >> gravity 

Answer 2

Similarity: both are forces which can effect the state of motion or rest of a body without physical contact.

Difference:
Gravity only attracts objects towards it where as an electrostatic force will repel a similar charge and attract an opposite one.