Common Linux Terminologies You Should Know

Binaries: These are not just the 0s and 1s you might think of when you hear "binary." In Linux systems, "binaries" refer to executable files, similar to ".exe" files in Windows. These are compiled programs or commands that are ready to run. Common directories where binaries are stored include /bin, /usr/bin, /sbin, and /usr/sbin. For example, /usr/bin contains user-level binaries like ls, cd, and applications such as Firefox and Chromium.

Directory: This is what you might call a "folder" in Windows. It’s a way to organize and store multiple files in one place. In Linux, folders are referred to as directories. So, whenever you see "directory," just think of it as a folder.

Home: The Home directory may not be familiar to Windows users. Except for the root user, every other user has their own directory under /home. For instance, a user named kali would have a home directory located at /home/kali/. Inside the Home directory, there are subdirectories like Desktop, Downloads, and Documents. For example, files on the desktop would be located in /home/kali/Desktop.

Root: Similar to the administrator account in Windows, Linux systems have a special user account called "root." This is the superuser account with full privileges. In Android, “rooting” a phone means gaining access to this root-level permission. With root access, most restrictions are removed.

Terminal: One of the most essential components in a Linux system is the Terminal. The terminal provides a CLI (Command Line Interface), which allows users to run commands and manage the system efficiently.

Shell: The shell is the interpreter environment used to run commands in a Linux system. The most commonly used shell is Bash (Bourne Again Shell), but others like C shell and Z shell also exist.

Script: A script is a file that contains a sequence of commands to be executed. Many hacking tools are scripts. These scripts are run through their corresponding interpreters—e.g., bash scripts are run with the bash shell, and Python scripts are executed using the Python interpreter. Python tools have become more common recently, making Python a popular language among hackers.

Bonus Tip: Linux systems are case-sensitive, unlike Windows. For instance, Kali and kali would be treated as different names in Linux. You could even have folders named Kali, kali, KALI, and KAli all in the same directory. So be very careful about capitalization when working in a Linux environment.

Permissions

One of the fundamental concepts in Linux is file permissions. Every file and directory has associated permissions that determine who can read, write, or execute them. These permissions are divided among three categories: the owner of the file, the group associated with the file, and others (everyone else). For example, a file might be readable and writable by the owner, but only readable by others. Permissions are often represented using letters (r for read, w for write, x for execute) or numerically (like 755). Understanding and managing permissions is crucial for maintaining both functionality and security in a Linux system.

Processes

A process is any running instance of a program. In Linux, everything you run—whether it’s a background service or a command in the terminal—becomes a process. Each process has a Process ID (PID) and may spawn child processes. You can view running processes using commands like ps, top, or htop. Managing processes is an important skill for Linux users, as it allows you to monitor system performance, identify misbehaving programs, and manually stop processes when needed.

Package Managers

Installing software on Linux is usually done via a package manager rather than downloading installers from websites. Popular distributions have their own package managers, such as apt for Debian-based systems (like Ubuntu and Kali) and dnf or yum for Red Hat-based systems. These tools simplify the installation, update, and removal of software packages, while also handling dependencies automatically.

Logs

Linux keeps a detailed history of system events through log files, which are essential for troubleshooting and system auditing. Most logs are stored in the /var/log/ directory. For example, syslog records general system activity, while auth.log tracks authentication attempts. Being able to read and interpret logs is a vital skill for system administrators and security professionals alike.