File System and User Types in Linux

File System in Linux

Linux, files are ordered in a tree-like structure, starting from the root directory. The root directory is from where the file system starts, and it further branches out into various subdirectories. A root is denoted with the forward slash, ‘/’, Under the root directory you can find different directories, please find the details about those directories.

• /bin contains binaries, that is, some of the applications and programs you can run.
• /boot contains files required for starting your system. If you mess up any files here, you may not be able to run your Linux and it is a pain to repair.
• /dev contains device files. Many of these are generated at boot time or even on the fly like if you plug in a USB pen drive into your machine, a new device entry will automatically pop up here.
• /etc contains the configuration and system files.
• /home is where you will find your users’ personal directories.
• /lib is where library files that your applications can use. 
• /mount is where you would manually mount storage devices or partitions.
• /opt is where is often where software is compiled by normal users.
• /proc contains information about the system, such as information about your CPU and the kernel your Linux system is running.
• /root is the home directory of the Administrator  (root user or superuser) of the system.
• /sbin is similar to /bin, but it contains applications that only the superuser will need.
• /usr contains files need to be shared by applications and services.
• /tmp contains temporary files, usually placed there by applications that you are running.

For more details, please check the below image and additional links.

User Types in Linux

There are three types of users that can be created  with different options in Linux as follows:

1. Root user: The root user has the highest privileges in the operating system.

   • It is the main user account in Linux, which is automatically created during the installation process.

   • The root user is the superuser who can access restricted files and install software and also has administrative privileges in the system.

   • This account cannot be deleted, but it can be disabled.

2. Regular user: This is the normal user account. During the installation process, one regular user account is created in the system.

   • Multiple regular user accounts can be created.

   • These accounts have moderate privileges inside the system and can access only those files and services which are authorized.

   • It is used for routine activities such as browsing the internet and other utilities.

   • These accounts can be deleted or disabled as per requirement.

3. Service user: Service accounts are created during the installation process by the installation packages.

   • Linux is widely used as a Server operating system in which services such as Apache and email have their own service accounts.

   • Having service accounts ensures the security of your computer.

   • Linux allows and denies access to various resources depending on the service.

Additional Links:

• Linux File System Explained