IAM definition
Identity and access management (IAM) is the set of policies, processes and technologies that ensure the right people and systems have the right access to the right resources at the right time. IAM covers creating and managing digital identities, authenticating users, authorizing what they can do, and reviewing and removing access when roles change.
Core components of IAM
IAM spans the full lifecycle of an identity, from the day a person joins or a service is created to the day access is removed. Identities include employees, contractors, customers, devices and non-human accounts such as service accounts and API keys, which often outnumber human users in cloud environments and are easy to forget during reviews. The main building blocks are listed below.
- Identity lifecycle: joiner, mover and leaver processes, often driven by HR systems.
- Authentication: passwords, MFA, passkeys and single sign-on.
- Authorization: roles, permissions and policies deciding what each identity can do.
- Privileged access management for administrator and root accounts.
- Access reviews and certifications to remove unneeded permissions.
- Auditing and logging of sign-ins and permission changes.
Authentication vs authorization
Authentication answers who are you, verifying identity through credentials such as a password plus a second factor. Authorization answers what are you allowed to do, applying rules to decide whether an authenticated identity can read a record, approve a payment or delete a server. Many breaches involve authorization failures, such as users accessing other customers' data, even when authentication is strong, which is why both need careful design and testing. Test both on every release.
Access control models
Role-based access control (RBAC) assigns permissions to roles, such as accountant or support agent, and users to roles, which is simple to understand and audit. Attribute-based access control (ABAC) evaluates attributes of the user, resource and context, such as department, data classification or time of day, allowing finer-grained policies. Relationship-based models, used by tools such as OpenFGA, suit applications where access depends on relationships like document sharing. Most products start with RBAC and add attributes later.
Whatever the model, the guiding principle is least privilege: give each identity only the access it needs, for only as long as it needs it, and grant elevated rights just in time rather than permanently. Temporary elevation with approval and automatic expiry is far safer than standing admin rights.
IAM in the cloud
Cloud platforms make IAM central to security. AWS IAM, Azure role-based access control and Google Cloud IAM control who can create, change or read every resource, and misconfigured permissions are a leading cause of cloud incidents. Good practice includes federating cloud access through the corporate identity provider, avoiding long-lived access keys, using roles for workloads, enforcing MFA on administrative access, and scanning for overly broad policies with tools such as IAM Access Analyzer.
IAM best practices
Centralize identities in one provider, automate onboarding and offboarding from HR data, enforce MFA everywhere, and review access regularly with managers who understand what their teams need. Monitor for dormant accounts and privilege escalation, and protect break-glass administrator accounts carefully. Nexzem designs IAM for client applications and cloud environments, from customer login and roles to least-privilege cloud permissions. Measure how long offboarding actually takes, since delays leave live access behind.