Critical is a multiplier chance to your damage. The reason why you stack critical is simple, would you like a slightly higher base damage, or a slightly higher chance multiplier. In practically all cases, the bigger chance multiplier will result in more damage.

Critical Hit: base chance at which you are likely to get a critical attack

Critical Rate: base chance plus any multipliers that add to it (for instance TenTen has a passive that gives a critical rate to your team)

Critical (in function stats): Nobody really knows because the Oasis devs (not a moderator) wont say how exactly it works. But having more of it will make it more likely for you to have a critical attack.

yeah..............
3 of them are all the same meaning ''the chance of causing a critical hit in battle''. doesnt have any difference between any of them

start to think generally right now I use sasuke vs kakshi training attack several times sasuke has a 30% more damage + 20tai that gives main light and 20% nin .. he showed red 22k and blue 40k damage color .... now use naruto no has nothing 3⭐ exercises double attack 6k6k red and 10k10k blue. now removed the critical runes had 21k critical now I have 14k the critical exerted by sasuke is 24 / 26k .. but the probability of blue critical dont appears. eye removed runes critical. now I barely got a critic in 48k.blue

Now I notice that the critical and critical hit are added in the stats information of the ninja .. critical is a possibility right now I'm in mission wanted I'm noticing that since I don't have the critical runes, most of my damage is red. not blue..the damage that is inflicted through critical of the runes is a possibility. if the possibility is obtained the damage injury comes into play. That's why the damage is blue ... but there are other damage colors (critical red and critical or metallic blue ... and I have noticed that when critical hit is used the damage will appear plus the word critical hit. and generally my damage is blue and little red and none says critical hit

we started I put this treasure I have absolutely nothing in power only level .. it removed in red damage 21 / 23k and blue damage 40 k I tried it many times ..