What is stage presence and how, if it all, can it be developed?

"Stage presence" refers to the ability to draw and hold the attention of an audience.  It is getting the audience to care about and like you when you play a character on the stage.

It does require some natural talent.  Just as there are people who naturally light up a room when they walk into it, so there are people who can naturally light up a stage.

But you can also develop and hone this ability through acting classes, practice, etc.  

But you do have to have a certain amount of natural talent.

Definition of stage presence

the ability to command the attention of a theater audience by the impressiveness of one's manner or appearance.

There has to be some to start with just like having the talent for acting.   Any skill can be honed but it can't be created from nothing.