Upgrading NETGEAR switches for increasing bandwidth

My client has a NETGEAR 24-Port 10/100 Rack mount Switch. And I want to know the advantages and disadvantages of upgrading it to a NETGEAR 48-Port 10/100/1000 Smart PoE Switch? The idea is simplified as: Server>>> NETGEAR 10/100 switch>>> Router>>>Internet. Can I plug the server to the NETGEAR 48/100/1000 Switch and another port will go to internet. Can my clients use the software data against the server so the bandwidth will increase in the server or the ports can only be used for trunking switches or the routers?
