The Citrix Device Posture service is a cloud-based solution that helps admins to enforce certain requirements that the end devices must meet to gain access to Citrix DaaS (virtual apps and desktops) or Citrix Secure Private Access resources (SaaS, Web apps, TCP, and UDP apps).
Establishing device trust by checking the device’s posture is critical to implementing zero-trust-based access. Device Posture service enforces zero trust principles in your network by checking the end devices for compliance (managed/BYOD and security posture) before allowing an end user to log in.
Find out more here: https://docs.citrix.com/en-us/citrix-secure-private-access/device-posture.html