Overview:
IAM:
IAM (Identity and Access Management) in Google Cloud Platform (GCP) is a core security service that defines who (user or service) has what access to which resources.

PAM:
PAM (Privileged Access Management) goes beyond IAM and is used to manage, monitor, and secure privileged accounts that have elevated permissions, often through third-party solutions.

Key Features
GCP IAM:
Role-based access control (RBAC)

Predefined, custom, and basic roles

Service account identity and access control

Audit logging via Cloud Audit Logs

Policy hierarchy at project, folder, and organization level

PAM (e.g., via third-party tools like CyberArk, BeyondTrust, or GCP integration with Identity-Aware Proxy or Access Context Manager):
Just-in-time (JIT) access provisioning

Session recording and monitoring

Credential vaulting (rotating passwords, secrets)

Elevation request workflows (approval-based)

Time-bound access for sensitive resources

Real-Time Use Cases
IAM:
Grant developers read-only access to specific projects for troubleshooting.

Allow DevOps team to deploy workloads by assigning them the "Editor" or a custom role with limited permissions.

Provide service accounts for CI/CD pipelines to interact with GCP resources securely.

Restrict access to BigQuery datasets only to data analysts using predefined roles.

Assign Cloud Storage Viewer role to finance team for monthly report access.

Set up organization-level IAM policies to enforce permission inheritance across projects.

PAM:
Allow system administrators just-in-time SSH access to production VMs for emergency fixes.

Require approval-based access workflows for database administrators accessing sensitive data.

Record all privileged user sessions for security auditing and compliance.

Rotate and vault credentials for service accounts or third-party API access.

Enforce time-limited access for external contractors accessing GCP projects.

Set up multi-factor access and contextual policies (location, device, identity type) before granting access to sensitive environments.

When to Use
IAM:
Use when you need standard access control across services for users, service accounts, or groups.

PAM:
Use when dealing with privileged accounts, sensitive environments, or regulatory compliance (e.g., SOX, HIPAA).

Advantages
IAM:
Native to GCP and easy to integrate

Granular permissions via custom roles

Integrated with GCP logging and monitoring

Free of charge (except logging and monitoring costs)

PAM:
Enhanced control over high-risk users

Real-time session monitoring

Prevents credential leakage and abuse

Ideal for securing DevOps pipelines, SSH/RDP, and cloud console access

Disadvantages
IAM:
Lacks advanced controls for privileged users

No session tracking or credential rotation

Static role assignments unless integrated with workflows

PAM:
Requires additional setup, often third-party

Can be costly (licensing, setup, training)

Adds complexity to access workflows

Cost (If Any)
IAM:
Free to use; costs may apply for Cloud Audit Logs or logging storage.

PAM:
Typically paid (especially for third-party tools). GCP-native components like Identity-Aware Proxy or Context-Aware Access may incur charges depending on usage and backend services.

Final Summary
GCP IAM is your go-to for standard access management across Google Cloud resources.

For enterprises with sensitive workloads, compliance needs, or admin users, integrating PAM solutions offers layered security with session controls, audit trails, and time-bound access.

Both serve different layers of the cloud security model—IAM controls access while PAM manages and monitors privilege.

Venkat C S