The meaning of Elective Surgery is surgery that is optional or not required to be done.
Some examples of elective surgery are weight loss surgery, plastic surgery, face lift surgeries, hair transplant surgery etc.
Surgery that is not elective would be emergency surgery such as heart surgery, kidney transplant surgery, internal bleeding surgery etc.
So basically any surgery that is not required medically to save your life would be Elective Surgery.
So if you want to go in for weight loss surgery then that would be considered elective surgery but if you need heart surgery that would not be elective surgery.
Elective Surgery usually requires you to pay out of pocket directly for the surgery.