Reports can take many different formats. How the reports is going to be used usually determines the report's format. For example, the users may only need to review and print the report, or they may need to use the report to copy, forward (as email attachment), analyze or graph report's data or perform calculations using the data.
Reports can be produced using specific software packages like Crystal Reports or Access, or using automation in MS Excel or MS Word, or in HTML and published on the Internet.
There can be more than tenfold difference in development time between two different type of reports that contain identical data. So, when we set up reporting functionality, first we try to find out if we can use the format that requires the least development time.
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Reports can also take a form of mail merge letters, published by the application and attached to correct recipients emails on the fly, so that the letter contains fields that are automatically filled in by the application.