Optimal means the best possible under the circumstances. When you find the optimal solution to a problem, you've found the one that works better than any other option available to you.

Think about packing your backpack for school. The optimal way to pack it puts the heaviest books closest to your back, keeps things you'll need first near the top, and balances the weight so your shoulders don't hurt. This approach works better than the alternatives.

Scientists and engineers talk about optimal conditions for experiments or designs. A plant needs optimal amounts of sunlight, water, and nutrients to grow its tallest and healthiest. Too much or too little of any ingredient makes it less than optimal.

When you're looking for an optimal time to practice piano (maybe after homework but before dinner, when you're alert but not rushed), you're seeking the arrangement that gives you the best results.

Sometimes people confuse optimal with perfect. But optimal simply means best given real-world limits and trade-offs. The optimal amount of time to spend on homework balances learning thoroughly with having time for other important activities. That's different from perfection, which might not even be possible or desirable.