In AskiaSurf, a campaign is a piece of ongoing research that comprises two or more discrete research waves. For example, a campaign might run continuously throughout the year, with the questionnaire being modified every month (each piece of research that uses a different version of the questionnaire constituting a wave). This campaign would therefore compromise 12 waves in its first year.
AskiaSurf reconciles the data from all of the campaign's waves, thus allowing you to perform data analysis across the various waves (e.g. to track the performance of a product over a year, or to compare sales in the same month in successive years).
AskiaSurf maintains a single file for each campaign, with the filename suffix .qew. QEW files can be opened in AskiaVista and AskiaAnalyse.