Three basic differences between Ron and Harry.
1. In danger, Harry's 1st instinct is to find a way to save as many people as he can. Ron's 1st instinct is to save Hermione 1st. Then others.
That's why Harry rescued Draco from the fiendfyre but Ron took Hermione on his broom and left the room(only came back when Harry asked him to save Goyle)
2. Harry would fight 100 Deatheaters alone to save the whole world. Ron would fight 100 Deatheaters alone to give Hermione a chance to run away and save herself.
That's why Ron begged bellatrix to torture himself instead of Hermione knowing full well she had tortured Neville's parents to insanity and barged into a room full of Deatheaters and disarmed Bellatrix. While Harry fought Alecto Carrow, Bellatrix and the malfoys for McGonagall, Sirius and various other people.
3. Harry is always for greater good. Ron is always for Hermione.
That's why when the chandelier fell on top of Hermione at the Malfoy manor, Harry's 1st instinct was to take all the wands from Draco's grip but Ron's 1st instinct was to pull Hermione out of the broken chandelier.