SOA VS Client Server Architecture

Application Logic
The Client  Server architecture include fat client that does bulk of processing and data-related logic and database server lying on the server.In the case of SOA options exist regarding where the application logic can reside and how it is distributed.

Application Processing
The Client Server architecture follow 80/20 where bulk of processing is done by the client and other database access and connection pooling is done by the server .In case of SOA each service has a explicit functional boundary and resource requirement.

Technology
Client Server Arch make use of 4GL programming languages and for performance reasons make use of 3GL programming languages.They also use vendor based RDBMS packages.In case of SOA XML data representation arch along with SOAP msg framework.It makes use of HTML,CSS,HTTP etc.

Security
In case of the client server the security is centralized at the server side.But security can also be realized on the client side.SOA heavily depends on WS-security framework for security.

Administration
In client server architecture the maintenance cost are high and administration problems are also involved.
SOA is also not that immune to client-side maintenance challenges.