Templates are single PDF documents with configurable fields that enable dynamic document generation within Signstack. They serve as reusable document definitions for creating personalized PDFs by mapping data from entities to fillable fields, signature fields, and other interactive elements.

Entities are structured data objects that conform to your schemas - think of them as the data sources that populate your template fields. For example, a real estate purchase agreement template might use entities like "buyer" (with name, email, address), "seller" (with contact details), "property" (with address, price, details), and "offer" (with terms and conditions). Each template has three main components: entity slots (which specify what data is needed), fields (which define where and how data appears on the PDF, with optional JSONata expressions that run on entity data to calculate field values or control field visibility), and roles (which define participants in e-signature workflows).

Templates follow semantic versioning (major.minor.patch) and lifecycle management (Draft, Active, Deprecated). This allows your templates to evolve over time while maintaining backward compatibility - draft templates can be edited freely, but once activated, they become immutable and require new versions for any changes.

Templates can be previewed directly within Signstack using scenarios, and can be rendered into final documents either standalone or as part of blueprints and workflows for document generation and e-signature processes.