# Overview
TIP
View the Core/HR API Reference Guides
Cornerstone's Core and HR APIs come in several varieties.
- Approvals - Enables developers to view, approve, and deny requests, as they appear on the user's Universal profile page.
- Employee API - Enables developers to view, create, and update employee records, custom fields, and CHR-specific attributes.
- OU API - Enables developers to fully view, create, and update OUs.
- Global Search API - Enables developers to search for people, training, and certification details.
- Other APIs - Use our Bulk, Reporting, or Data Exporter API frameworks to operate upon Employees, OUs, and Capabilities en masse. Details on these APIs are available under their respective guide pages.