An idea is a thought or plan that forms in your mind. When you think of a way to solve a problem, imagine something that doesn't exist yet, or wonder about how things work, you're having ideas.

Ideas can be simple, like realizing you could organize your desk differently to find things faster. They can be creative, like imagining a new character for a story you're writing. They can be important, like figuring out how to help a friend who seems lonely. Scientists have ideas about experiments to try. Inventors have ideas for new machines. Artists have ideas for paintings or songs.

Some ideas pop into your head suddenly, like when you're in the shower and realize the perfect solution to something that's been bothering you. Other ideas take time to develop, growing clearer as you think them through or talk them over with others.

Good ideas often come from combining things you already know in new ways, or from asking “what if?” questions. The best ideas usually need work to become real. Thomas Edison had the idea for the light bulb, but it took hundreds of experiments to make it work. When people say “that's a good idea,” they mean your thought seems useful, interesting, or worth trying.