Understand react and meteor working together

Hi everyone

I just started learning Meteor with React, in official tutorial i don’t understand, why for example find or insert task method in client side [ ReactJs (Front end / Client) ] normally, it will be in backend in server.

Anyone can explain me how it work in MeteorJs and Thanks.

Normally in Meteor, it’s in both, to provide optimistic UI. Client changes are instant and will eventually (round trip to server time) be confirmed or denied by the server.