Let me begin by explaining the two concepts first. When you load a workbook on Excel Services, you are given two options to open the workbook on Excel.
1. Snapshot: This provides users a copy of the workbook with all the formulas behind the numbers stripped out.
2. Open in Excel: This provides users with a copy of the original workbook. Changes to the read-only version of this workbook will not appear in the original workbook on Excel Services.
What the Diff?
• Snapshot has all the formulas behind the numbers stripped out.
• Some features within snapshot are stripped out: Conditional Formatting
Why have Snapshots?
Security! Again, Snapshot is another excellent example of how Excel addresses security. This technology will allow authors of these workbooks to prevent readers from surfacing formulas (which could be considered confidential).
Tracy is a Sales Manager that works for a software consultation company. One of her primary tasks is to conduct client visits and advertise how their company could benefit their client. In order to convince her clients of the benefits of working with her company, she would like to provide each client with a workbook indicating how other company's have benefited from using her company's products. This Excel Services workbook contains a chart indicating that their previous anonymous client have reduced their IT expenditure by 35% over 8 months after using their product. However, Tracy does not want to reveal how the number 35% was derived (via external data or other manners). As a result, she provides each potential client with a Snapshot of the original workbook.