Science

Systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
— Wikipedia

Scientific method

The scientific method is the name given to the methods used by scientists to find knowledge. The main features of the scientific method are:

Scientists identify a question or a problem about nature. Some problems are simple, such as “how many legs do flies have?” and some are very deep, such as “why do objects fall to the ground?” Next, scientists investigate the problem. They work at it, and collect facts. Sometimes all it takes is to look carefully. Some questions cannot be answered directly. Then scientists suggest ideas, and test them out. They do experiments and collect data. Eventually, they find what they think is a good answer to the problem. Then they tell people about it. Later, other scientists may agree or not agree. They may suggest another answer. They may do more experiments. Anything in science might be revised if we find out the previous solution was not good enough.

In other words science is what we do to find out about the natural world.
— Simple English Wikipedia