How do you list files and directories in Linux?

Use the ls command to list files and directories. ls alone shows files in the current directory. Common options: ls -l shows a long listing with permissions, owner, size, and date; ls -a shows hidden files (those starting with a dot); ls -lh shows human-readable file sizes; ls -R lists recursively; ls -lt sorts by modification time. Example: ls -lah /var/log lists all files in /var/log with human-readable sizes including hidden ones.