In the client applications in which more computer are connected in network
In the application project use a connection string like this “server=computer name where the server resides; username=user name ; password=user password; database= explicit path of the database in the server machine\mydb.gdb"
You have to install in the client machine the .net framework.
You have also to copy on the in the client machine only the escecutable of the application and to install the FirebirdClient-2.0.1.
You don't need install neither the Server of Firebird neither the client library in the client machine.
If the server machine is firewalled let open the port n. 3050 in the firewall.
There's no other you have to do.