Why do I need a database? While not everyone needs a database, having one can make business life and understanding the flow of information easier for everyone involved.
Information Management is huge! While I control what comes into my personal space, it is difficult and hard to control what enters your business environment. You want to receive offers from companies, you want people to know about your business, because you need to sell your business to make money!
Controlling the flow of information, how it is stored, how long to keep it, what do I do with it, is what many people do all day long. We have emails, downloaded files, faxes, paper mail, magazines, catalogs, and the list will continue. Sometimes the amount of paper or information is so overwhelming people just ignore it; or they throw everything out. This is not an answer, just a way to make the problem seem to go away. If you are in business - you could lose everything.
Database Management Software edit
There are a substantial number and variety of database management software available, some of which are freely available while majority of them are paid. They also differ from the underlying model they support( e.g. relational database models such as; MS-SQL Server, IBM DB2, and MySQL Server). These software programs handle the majority of the most common tasks by default, while offering excessive control to the database administrator or developer.