Well, to compare "soap opera" and "space opera", I get:
1.It's huge, complex, detailed and obtuse. Unless you start at the beginning, it is utterly impossible to just watch an episode or two and "understand and get" what is going on in the story. Your ONLY option is to watch the whole show, and you have to accept that for some time you will be clueless and won't "get" things in the show.
2.There are lots and lots and lots and lots of characters. Characters come and go, and can be very hard to keep track of in the story.
3.No Main Characters. While a story thread my feature a character, they are by no means a "main" character. As the story moves along, old characters will fade and new ones get a spotlight. No character has plot armor and can die at any time. No character is the "special chosen one" that the whole universe revolves around.
4.Long storytelling with no short cuts. When the planet Pangus makes a space force, we get to see it slowly be built over a vast course of time. If a character falls for some addiction it's a plot point for a long, long time. There are no quick fixes or reset buttons.
5.There is no Hollywood Endings like the demi god super hero character shoots a thingy and ALL of the alien/robot/whatevers in the whole army are automatically defeated. Heroes do not disarm bombs by cutting the red wire with one second left. Things are done the hard way. The only way for a rebels to defeat the evil empire is by and endless war of attrition until the empire can't fight back.