In Previous Years Questions
In Linux, user accounts are essential for managing access to system resources and maintaining security.
There are three main types of user accounts, each with a specific role:
1. Superuser (root):
- Possesses full administrative privileges.
- Can access and modify any file or system configuration.
- Used for system administration tasks that require elevated permissions.
- Should only be used when necessary due to the security risk of having full access.
2. Regular Users:
- Standard accounts used for daily work.
- Have limited access to system resources and files depending on their permissions.
- Used for tasks like running applications, working with files, and accessing the internet.
- Can be restricted further by assigning them to specific user groups.
3. Service Accounts:
- Created specifically to run system services.
- Have limited access to resources and are not intended for interactive use.
- Often have restricted permissions and are used to minimize the risk of unauthorized access to the system.
| User type | Role | Usage |
| Superuser (root) | System administration | Installing software, managing users, modifying system configurations |
| Regular Users | Daily work | Running applications, working with files, accessing the internet |
| Service Accounts | Running system services | Database services, web servers, email servers |
Additional User Types:
- Guest Users: Limited access to the system, typically used for temporary access.
- System Users: Used for specific system tasks, such as running backups or managing logs.
User Identifiers:
- UID (User ID): Unique numeric identifier assigned to each user account.
- GID (Group ID): Identifies the group(s) a user belongs to, influencing their permissions.