Shell is a program that exposes operating system services to users. Shells use either command-line interface (CLI) or graphical user interface (GUI). Shells are special applications that use kernel API like other programs. Shells manage user-system interaction through input interpretation
UI design focuses on maximizing usability and user experience across various electronic devices. Design process involves empathy, problem definition, ideation, prototyping, and testing. Good UI design balances technical functionality with visual elements
df command shows disk space usage with -h option for human-readable format. df command only shows mounted filesystems, needs explicit mounting for others. Alternative commands include du, ls, stat, fdisk, and dust
Colors significantly impact UI/UX and user engagement in applications. Colors can be represented by names like 'white smoke' or codes like #FF0000
.BIN files are installation binaries for programs. Files need to be executable using chmod command. Downloaded files should be checked for installation instructions
Original code provided syntax error in Python 3.3.1. PhotoImage class supports .gif, .pgm, and .png formats. Image format must match file path. PIL library installation required for Python 2.7