Types of User Accounts in Linux

User accounts represent identities that authenticate to the system and can use authentication credentials to do specific tasks.

Individuals who will be using the Linux computer should have their own unique user accounts. Administrators will use these accounts to control the user's access to files, directories, and commands on the system. Each account is referenced by the system using a user ID (UID), rather than a name. Names are used for the convenience of the users.

User accounts have several attributes, including password information, group memberships, expiration dates, comments, etc.

Types of User accounts:

There are three different types of user accounts:

1. Root
2. Standard user
3. Service

Root User Account:

1. There are two roles played by the root user.
   i) As a local administrator.
   ii) To provide a security context for some applications and commands.
2. A user logged on as root can do administrative tasks such as password resets, system configuration changes, user account management, etc.
3. It is a bad practice to log on to any system with administrative credentials directly.

Standard User Account:

1. Standard user accounts represent regular system users who may log on to run applications, configure databases, build websites, etc.
2. Most tasks that a user should be doing on the system should only require standard user account privileges. 

Service Account:

1. Applications also consume resources on the system, so they are often represented by their own service accounts.
2. These accounts are usually specific to the service (such as the httpd web service or a database service). 
3. They are disabled for regular log on, and the accounts are usually created as part of the service installation process.