Authentication is the process of verifying the identity of a user, system, or device before granting access to an application or service. It ensures that only authorized users can access protected resources by confirming who they are.
In software and web development, authentication is commonly implemented during login systems, where users provide credentials such as usernames, passwords, or biometric data. It is a core part of application security and is often combined with authorization, which controls what an authenticated user is allowed to do.
For example:
- A user logs into a banking app using a password and one-time OTP verification.
- Social media platforms like Facebook or Instagram require email and password authentication.
- A company uses single sign-on (SSO) to let employees access multiple systems with one login.
- Mobile apps use fingerprint or face recognition for secure access.
Common technologies and concepts related to authentication include:
- Username and Password
- Multi-Factor Authentication (MFA)
- One-Time Password (OTP)
- OAuth
- JWT (JSON Web Token)
- Session Management
- Biometric Authentication
- Single Sign-On (SSO)
