Context is lacking, but I'm going to assume that by 'application', they mean the SolarWinds application suite. If this assumption is correct, they looking for someone that understands what it takes to install SolarWinds, e.g. (1) the requirements for the IIS web server, whether physical or virtual; (2) what is required for the supporting SQL server, that it generally needs to be installed on a separate server, and for large environments must be very powerful and running RAID 1+0; (3) how large of an environment can be supported with a single polling engine, and when additional polling engines are required; (4) considerations regarding management protocols, SNMP v2 vs v3, when WMI is required and the limitations of this protocol; and (5) special requirements for specific modules, such as the separate, dedicated database for the NetFlow module, and the virtual server for the Virtualization module.
If, by 'application', they're referring to applications in general, well, 'never mind'.
I know the question itself is very vague and I really don't know how to approach it but anyways thanks for the advice really appreciate it.