Specify the properties for this Search Service Application. The settings you specify here can be changed later using the ...

Specify the properties for this Search Service Application. The settings you specify here can be changed later using the properties button in the Manage Service Applications page.
A new Search Service Application will have an initial topology with all components on one application server and all databases on one database server. The topology of this application can be changed later using the Modify Topology link located on the Farm Search Administration page.