A GOOD PLACE TO BEGIN
Pull apart the logic behind the screen. Try it, change it, see what happens.
A visual field guide to the ideas shaping our digital world. Start with a question; leave with a little more wonder.
Computers only understand 0s and 1s. Click the bits to flip them. Each bit is worth double the one on its right, and the ones that are ON add up to the number.
Sorting is one of the most studied problems in computer science. Pick an algorithm and watch how it puts the bars in order.
The Caesar cipher hides a message by shifting every letter along the alphabet. It is one of the oldest encryption methods and is said to have been used by Julius Caesar.
Top row: the letter you type. Bottom row: what it turns into.
Challenge: switch to Decrypt, use a shift of 3, and decode Khoor Zruog.
Logic gates are tiny decision makers inside a processor. Change the inputs and gate to see how a Boolean rule becomes an output bit.
| A | B | A AND B |
|---|
A data structure is a way to arrange information so a program can use it. Compare a stack, which serves the newest item first, with a queue, which serves the oldest first.
Routers pass packets along links to reach a destination. Pick two points, then find the route with the lowest total delay.
Ask the sample books table a question. Try SELECT, WHERE, ORDER BY, or LIMIT; the small dataset runs right here in your browser.
This learning sandbox supports SELECT, a single basic WHERE condition, ORDER BY, and LIMIT. It uses a small built-in example table.
A regular expression is a pattern for finding text. Edit the pattern or sample, then see each match highlighted as you type.
The operating system scheduler decides which ready process gets CPU time. Compare first-come-first-served, shortest-job-first, and round-robin scheduling.