Explore the binary (base-2) number system used by computers to represent all data. Convert between binary, decimal (base-10), and hexadecimal (base-16) representations. Understand place values as powers of 2, practice binary arithmetic, and learn why computers use binary (two states: 0 and 1 corresponding to off/on electrical signals). Discover how binary represents numbers, text (ASCII/Unicode), images, and all digital information.
Explore data compression techniques that reduce file size for efficient storage and transmission. Compare lossless compression (original data perfectly recoverable, used for text and executables) with lossy compression (some data discarded, used for images/audio/video). Visualize run-length encoding (RLE) that replaces repeated sequences with count-value pairs, and understand Huffman coding, LZW, and how compression ratios balance file size with quality.
Understand how digital images are represented as grids of pixels, each storing color information. Explore the RGB color model where each pixel combines Red, Green, and Blue values (0-255) to create millions of colors. Learn how resolution (pixel dimensions) and bit depth affect image quality and file size, and understand the relationship between pixels, screen resolution, and how computers store and display visual information.
Explore how the Internet works through protocols and routing. Understand the TCP/IP protocol suite: IP addresses for device identification, TCP for reliable data transmission with error checking, and UDP for faster connectionless communication. Visualize packet routing through networks, DNS (Domain Name System) translating domain names to IP addresses, and how routers use routing tables to forward packets along optimal paths across the global Internet infrastructure.
Explore encryption techniques that protect data confidentiality by transforming plaintext into ciphertext. Practice classic ciphers like Caesar cipher (shift each letter by a fixed amount) and substitution ciphers. Understand symmetric encryption (same key for encryption and decryption) versus asymmetric encryption (public/private key pairs). Learn about modern encryption standards like AES, RSA, and the importance of cryptography in securing digital communications and online transactions.