How does Binance calculate the open and close values in the candle plot for Spot Trading?

Hello. I've heard that the open and shut values are related to the first and last transaction of the time vary (day, week...). Nevertheless, I observed the open worth is identical as the close worth of the previous bin, which sounds bizarre to me. As cryptos are decentralized, shouldn't we've got totally different values for that? Couldn't we now have an outlier transaction in the first transaction of the day that's totally different from the final transaction of the day before today?

Also, prices within the dashboard (Spot trading) are calculated based mostly on only Binance transactions or other exterior sources (like other platforms)?