here you go......

A Condition feature that forces a query to retrieve only the data that meets specified criteria.condition is placed on a report query to show the specific data. To define a condition Name Description and Where clause are required

A Filter enables you to view only necessary data in a report.i.e it allows you to restrict the no.of rows displayed in the report they effect only the data currently displayed in the block but not query results

Ex:select values for a variable in the report to apply a simple filter

An added point here is that a condition is used to fetch selected data from the data source (data base) while the filter is used to fetch selected data from the data cube.

Also you apply a condition in DeskI using Edit data provider while filter is applied using Slice and Dice Panel Filter and by right clicking on the Report pane.