In layman terms, a database is a place where information is stored. If you are familiar with Microsoft Excel, a database is conceptually the same thing. In Excel, each worksheet contains a logical set of information presented in columns and rows. So if you have an employee worksheet, the first column could be Name, the second column Age and so forth. The rows will then represent individual employees.
This is exactly what a database does except it stores these information much more efficiently and effective. So, once you have about 100,000 rows in Excel, it starts to get slow. A database allows you to store millions of records without making it slow for you to retrieve data.