What is the relationship between volume and size?

Here is a snapshot of information about the last trade (tick), best bid/ask and 24h volume of BTC-EUR:

"trade_id":3194456
"price":"9229.01"
"size":"0.00865274"
"time":"2020-09-26T14:14:28.316023Z"
"bid":"9228.99"
"ask":"9229.01"
"volume":"1904.22812625"

What if any is the relationship between "size" and "volume"? As volume is the total amount of BTC-EUR traded over a 24hr period is "volume" equal to the sum of all "size" attributes for all of the previous trades over a 24hr period?