Please note: Your exact menu names, the look of the page, etc. will vary depending on customizations that have been made to your install, your theme, and what version you are using.
CiviCRM is a Customer Relationship Management database system. It works similar to Access or other such databases, except that this system is available online instead of residing on one person's computer.
This CRM allows multiple people to have access (if you choose to) via individual user names and passwords. It is also available anywhere you have internet access.
The benefit of a system like this is that multiple people can easily have access, duplication of information across multiple files is no longer an issue, and you can have access from anywhere with internet access - not just at the computer with the database.
Many campaigns and organizations find that they end up with multiple copies of their lists/databases/spreadsheets, each with different information. One person makes a copy so they can have one on their computer, they input information into that file, and now you have two different files. And the longer your organization has been around, the more such files you're likely to have.
This CRM allows you to import all the information from your spreadsheets and databases and store it in one, easy to access place. You can even export it into a file in case you need to take it somewhere without internet access.
Also, you can allow people to update their own information, if you choose.
Setting up CiviCRM can be difficult, as there are many settings that have to be done to ensure that your installation works. As such, it is recommended to get someone who knows CiviCRM to help you with this.
CiviCRM allows you to collect information, such as from volunteer and sign up forms, take online donations (when connected to a merchant account service), allow people to sign up for memberships, have paid events, and more. Future versions of the software will have additional features.
CiviCRM has also recently added a free how-to book and there is now a printed book as well.
