Say you have a useEffect that calls an API: maybe firebase or parse. That useEffect only gets run on the client. For the server side render: it runs the react code based on the initial props and takes that first rendering and creates the static html from that. When that static html is run on the browser it will run react and subsequent renders can update the dom.
Say you have a useEffect that calls an API: maybe firebase or parse. That useEffect only gets run on the client. For the server side render: it runs the react code based on the initial props and takes that first rendering and creates the static html from that. When that static html is run on the browser it will run react and subsequent renders can update the dom.