Spreadsheets are powerful tools, but, as their name suggests, they are just computerized columnar pads. Excel still is not designed to do what a database can do. This is why they make a program called Access. Access is only provided in professional versions of MS Office because it is considered a "serious tool" which not every business needs. Businesses often start by using spreadsheets as a step up from paper systems, but then they grow to the point where the business is depending on them, and the spreadsheet either can't meet the needs, or is taking valuable resource time from skilled employees who really should not have to crunch numbers and run macros to get the business information they need. This can be very dangerous and cost in-effective. The danger comes from the fact that spreadsheets are inherently poor at forcing good data entry practices, so keyboard errors start corrupting the data. A spreadsheet is hard to automate with sophisticated programming, so someone is often responsible to generate company reports by moving data around or using mail-merge. A spreadsheet offers no data integrity. Try sorting a single column some time and watch as your data gets scrambled.

 

Databases can enforce rules on the data such as "for this field, only allow one of these values to be entered". Spreadsheets are a good tool to prototype what you want to run your business, but you should quickly consider moving to a database to keep your data safe and orderly. Converting a project from a spreadsheet to a database is a relatively simple process, provided you do so early.