As Jeeva mentioned, it stands for "Configuration Item". For questions like this, you'll often find the answer in the glossary section of the user guide: https://docs.dataminer.services/user-guide/Reference/glossary/glossary_a_to_l.html
I believe CI stands for Configuration Items.
In IDP, we use CI Type to add identifiers that we can use to discover the devices in the network. Initially, when we perform Element Provision via IDP, we search by using the IP ranges. During this process, we discover many devices that can come from multiple brands, models, and firmware versions.
By utilizing CI type, we can add identifiers that enable us to filter the devices based on the Discovery Result obtained through the element discovery process using IP ranges.
As shown in the image below, we can define multiple CI types for the Arista Driver, each with a unique identifier based on the Discovery Result. This will allows us to define different protocols, alarm templates, trend templates, and more, based on the specific CI type.
You can also refer to the nice Dojo Article to know more: