Identification of Actors in a Social Media System

In the context of a Social Media System, actors are defined as any external entities (human users or other systems) that interact with the platform to perform specific operations. Understanding these actors is crucial for designing use cases, understanding access levels, and defining system boundaries. The following are the primary and secondary actors typically identified:

1. Registered User (Primary Actor)

This is the core user of the system who signs up and interacts with the platform regularly. The registered user can:

• Create and manage their profile
• Post text, images, and videos
• Follow other users and get followed
• Like, comment, and share posts
• Send direct messages
• Receive notifications

This actor represents the typical social media participant and performs the most frequent operations in the system.

2. Administrator (Secondary Actor)

The administrator is responsible for managing the overall system health, enforcing platform rules, and ensuring data integrity. Their responsibilities include:

• Moderating reported content or users
• Managing banned users or deleted accounts
• Overseeing system logs and audit trails
• Configuring platform settings and thresholds

Administrators have elevated permissions not available to normal users and often use an admin dashboard.

3. Guest/Anonymous User (Optional Actor)

A guest user is someone who browses the platform without signing in. Their access is limited and may include:

• Viewing public profiles and posts
• Accessing trending or promotional content
• Registering or logging in to become a full user

This actor helps in onboarding and improving accessibility for first-time visitors.

4. External Authentication Provider (System Actor)

In cases where third-party authentication is used (e.g., Google, Facebook login), these systems act as actors during the sign-up or login phase. They are responsible for:

• Verifying user credentials via OAuth
• Returning access tokens for session management
• Ensuring security of user identity

This actor interacts with the system only during specific operations like login or authorization.

5. Notification Service (System Actor)

This external or internal service is responsible for handling notifications and alerts. It performs actions such as:

• Sending push notifications to user devices
• Delivering email alerts
• Handling in-app notification updates

It ensures real-time communication of user interactions, enhancing engagement and awareness.

6. Messaging Server / Chat Engine (Optional System Actor)

In systems where real-time messaging is supported, a dedicated messaging server may be integrated. It supports:

• Instant messaging between users
• Maintaining chat history and synchronization
• Ensuring delivery and read receipts

This actor enables scalable, asynchronous communication across users.