Simple means easy to understand or do, without complicated parts or steps. A simple math problem like 2 + 3 takes seconds to solve, while a complicated one might involve fractions, decimals, and multiple steps. A simple recipe might just need you to mix three ingredients, while a complex one fills a whole page with instructions.

Something simple is straightforward and uncomplicated. A bicycle has a simple design compared to a car: pedals, wheels, a chain, and handlebars work together in a way you can see and understand. The rules of tic-tac-toe are simple enough to explain in one minute, while chess takes much longer to learn.

People sometimes use simple to mean plain or basic, without extra decoration. A simple bedroom might have just a bed, desk, and lamp, while a fancy one could have curtains, rugs, artwork, and shelves full of things. Scientists and engineers often try to find the simplest solution to a problem, the one that works well without unnecessary complications.

When something seems simple, it's usually easier to use, easier to fix if it breaks, and easier to explain to others. But don't confuse simple with simple-minded or easy to figure out: some of the most powerful ideas in history, like treating others the way you want to be treated, are beautifully simple yet profound.