Why does Ravencore wallet sync.

Hi. new here and Id love to understand why my ravencore wallet takes 5 hours to synchronize with the network and what does that actually mean, what is the wallet doing?

https://preview.redd.it/53dx8yifc2o61.png?width=1127&format=png&auto=webp&s=a33fa63d71c4b1fbfc203cab1406e23b5e720ecf