How SQL server stored procedure reduce network traffic?

When an application needs to retrieve one or more rows from SQL Server and then takes some action on this data, such as Inserting, Updating, or Deleting rows in the database based on the data retrieved, network traffic is significantly reduced if all this code is stored in a stored procedure. As before, it only takes a single RPC call to execute a stored procedure. But if all the code to perform these steps is not in a stored procedure, but located in the application, network traffic can be high.

For example, first, the application has to send the Transact-SQL code to SQL Server (lots of potential network traffic). Then SQL Server has to return the result set back to the client, then the client has to use the data, and then send additional requests (INSERT, UPDATE, DELETE) to SQL Server, and then SQL Server has to respond back to the client, and so on, until the task is completed. As you can see, this can generate a lot of network traffic. But if all the work is being done from within a stored procedure, network traffic is greatly reduced

Yes, your right, but when two or more application accessing same database, then what happened.
Because, i did develop application in .net, and data is on server, when more than two application access sql server, two or three application can perform operation but some can not complete operation, Time out expired message displayed for application, when more than two.
i did set unlimited time for sql server, but this is not working properly, if you have any solution. Plz help me