From time to time, we get requests from people that want to export their database for back up purposes or to share with another organization. There are lots of tables in your Powerbase and they are linked from one to another using various techniques, but usually the contact id is the important one.
These are your options:
1) Take a backup of the entire mysql database.
This gives you EVERYTHING including some of the obscure files that you may not need. You are in complete control over the data, but it requires using a mysql installation to delve into it. You'll need those skills or help from someone that has those skills. We backup your data every day, but we don't enable the option for users to make an offline backups as a default. Contact Powerbase support to get the option set up if you need it.
2) Export the individual files using the Powerbase interface.
This process requires repeating a number of steps. Essentially, you search for the data you want and then take the option to export it as a CSV file. CSV files are often used to bring data out of one system and into another. The CiviCRM manual has documentation on exporting.
In addition, we've made a screen cast on how to do export Contacts and addresses.
There is only one contact record per person or organization, but each contact record can be linked to multiple contributions or event attendance or other activities. To export Activities, Event Participation, and Contribution history, you will need to search for each record type and export them. The CiviCRM manual in the links above describes how to select which fields to include in your export file.
This Powerbase tip explains how to export contributions
Along with using the export feature from the option menu, you can also create reports and download the results as a csv file. This can allow you to bring together data from multiple tables into one format.