https://osu.ppy.sh/help/wiki/Score/#score
Score is based distribution and order of the judgments (300g/300/200/etc..) you get during the play.
When the play has decent accuracy (mostly getting 300g or 300 judgments), getting several 200s or lower judgments (except Miss) in a row tends to give you a bigger score penalty compared to having that same amount of bad judgments but more spread out.
Getting several misses (or 200 or lower judgments if the play has bad accuracy overall) in a row gives a lesser score penalty than getting those same judgments spread out.
Just after a miss, the difference between 300g and 300 judgments is bigger.