# How do I know what data I have available?

If you’re not sure what data (events and attributes specifically) you’re sending to Customer.io or how your data is used, you can find that information in the **Data Index**. You’ll find the Data Index in the left-hand menu, just below *Activity Logs*.

[![A page titled data index. There are two tabs in a table below the title. The first tab is selected and reads Attributes. There are a list of attributes like address and birthday listed. The second tab is Events.](https://docs.customer.io/images/data-index.png)](#17beb4bd607f4272be0584e3580d0f44-lightbox)

Here, you’ll find all of the attributes and events flowing into your Customer.io account via your chosen integration method. You can see:

*   All of the events and attributes you have
*   Where they’re being used (segments, campaigns)
*   How they’re being used (as a trigger, filter, or Action Condition)
*   For events, the data associated with each and when it was last seen
*   For attributes, we list all of the attributes you have for your users, and when each was last changed or added

Head over to the [Data Index introduction](/journeys/using-data-index) for more details on how to navigate; otherwise, feel free to explore!