Simplify the following text for a Grade 6 native English-speaking person.
Original: For example , a data set containing all the real-estate transactions in a town can be grouped by the year each transaction occurred , the sale price , a buyer 's last name and so on .
Simplified: For example , a database has all information about real-estate sales in a town . This information can be grouped by year , or by sale price , or by buyer 's last name and so on .