1. What is Linux?
Linux is an open-source operating system based on Unix. It is widely used in servers, cloud computing, mobile devices, and embedded systems.
2. Who developed Linux?
Linux was developed by Linus Torvalds in 1991. It was released as a free and open-source operating system kernel.
3. What are the main features of Linux?
Linux is secure, stable, and multi-user. It supports multitasking and runs on many hardware platforms.
4. What is a Linux distribution?
A Linux distribution is a complete operating system built around the Linux kernel. Examples include Ubuntu, Red Hat, CentOS, and Debian.
5. What is the Linux kernel?
The kernel is the core part of the Linux operating system. It manages hardware, memory, processes, and system calls.
6. What is the Linux shell?
The shell is a command-line interface that allows users to interact with Linux. It takes user commands and sends them to the kernel for execution.
7. What are some common Linux shells?
Bash, Sh, Zsh, and Ksh are common Linux shells. Bash is the most widely used default shell.
8. What is the root user in Linux?
The root user is the superuser with full system access. It can perform any administrative task on the system.
9. What is the home directory in Linux?
The home directory stores personal files of a user. Each user has a separate home directory under /home.
10. What is the Linux file system?
The Linux file system organizes files and directories in a tree structure. The root directory / is the top-level directory.
11. What is the difference between / and /root?
/ is the root directory of the file system. /root is the home directory of the root user.
12. What is a process in Linux?
A process is a running instance of a program. Each process has a unique process ID (PID).
13. What is a daemon process?
A daemon is a background process running without user interaction. Examples include sshd and crond.
14. What is the use of the ls command?
The ls command lists files and directories. It helps users view contents of a directory.
15. What is the use of the pwd command?
The pwd command displays the current working directory. It helps users know their current location in the file system.
16. What does the cd command do?
The cd command changes the current directory. It is used to navigate between directories.
17. What is the cp command used for?
The cp command copies files or directories. It is commonly used for backups or duplication.
18. What is the mv command?
The mv command moves or renames files and directories. It can change file location or file name.
19. What does the rm command do?
The rm command deletes files or directories. It permanently removes data, so it should be used carefully.
20. What is file permission in Linux?
File permissions control access to files and directories. They include read, write, and execute permissions.
21. What are the three types of permissions?
Read (r), Write (w), and Execute (x). These permissions apply to owner, group, and others.
22. What is the chmod command?
chmod is used to change file permissions. It can use numeric or symbolic modes.
23. What is the chown command?
The chown command changes file ownership. It assigns a new owner or group to a file.
24. What is a soft link in Linux?
A soft link is like a shortcut to a file. It can point to files across file systems.
25. What is a hard link?
A hard link directly points to the file’s inode. Deleting the original file does not remove the hard link.
26. What is the grep command?
grep is used to search text in files. It finds matching patterns or keywords.
27. What is the use of the find command?
The find command searches files and directories. It is useful for locating files based on conditions.
28. What is the ps command?
The ps command displays running processes. It shows PID, CPU usage, and memory usage.
29. What is the top command?
top shows real-time system performance. It displays running processes and resource usage.
30. What is the kill command?
The kill command stops a running process. It uses process IDs to terminate processes.
31. What is a package manager?
A package manager installs and manages software. Examples include yum, apt, and dnf.
32. What is the tar command?
tar is used to archive multiple files. It helps in backup and file compression.
33. What is the difference between vi and vim?
vim is an advanced version of vi. It provides syntax highlighting and extra features.
34. What is a mount point?
A mount point connects a storage device to the file system. It allows users to access files on that device.
35. What is the /etc directory?
/etc stores configuration files. Most system settings are defined here.
36. What is the /var directory?
/var stores variable data like logs and cache. Log files are usually stored in /var/log.
37. What is the /bin directory?
/bin contains essential user commands. These commands are required for system operation.
38. What is the /sbin directory?
/sbin contains system administration commands. These are mostly used by the root user.
39. What is a cron job?
A cron job schedules tasks automatically. It runs commands at specified times.
40. What is crontab?
Crontab is used to manage cron jobs. It defines scheduled tasks for users.
41. What is the df command?
df shows disk space usage. It displays available and used storage.
42. What is the du command?
du shows disk usage of files and directories. It helps identify large files.
43. What is the whoami command?
whoami shows the current logged-in user. It is useful for checking user identity.
44. What is SSH?
SSH provides secure remote access to Linux systems. It encrypts communication between client and server.
45. What is the uname command?
uname displays system information. It shows kernel name and version.
46. What is swap space?
Swap space is used when RAM is full. It improves system stability under heavy load.
47. What is the history command?
The history command shows previously executed commands. It helps in repeating or debugging commands.
48. What is a log file?
Log files store system activity records. They help in troubleshooting issues.
49. What is the difference between GUI and CLI?
GUI uses graphical elements like windows and icons. CLI uses text-based commands for interaction.
50. Why is Linux popular in servers?
Linux is stable, secure, and lightweight. It is cost-effective and highly customizable.
Conclusion
Linux interview questions for freshers mainly focus on understanding basic commands, file systems, user management, and core concepts. Mastering these fundamentals helps candidates confidently answer technical questions and perform well in practical interview rounds.
Regular hands-on practice with Linux commands and real-world scenarios is the key to success. By preparing these commonly asked Linux interview questions, freshers can build a strong foundation and improve their chances of clearing Linux and system administration interviews.
