# Building Blocks Both workflows are assembled from the same core pieces: a **project** to hold your work, **image layers** for the imagery you're assessing, and — for the trained-model workflow — reusable base **models**. You'll usually arrive at these pages from a step in a workflow; they're gathered here for reference and detail. - {doc}`Projects ` — create and organize the work for a disaster event. - {doc}`Image layers ` — add and manage imagery, and choose the Standard or Building workflow. - {doc}`Model catalog ` — reuse a trained model as a base model for future training runs.