Science is...

• always changing
• mostly theory because of possibilities of advancement
• something that is believed
• determines cause and effect
• the study of the world around us
• tries to answer the question "Why?" (But doesn't religion also try to answer this?)
• a search for order and understanding
• tests, experiments, theories, models
• "what is true about something now will be wrong in a few years...."
• there are always unknown questions and answers
• Consistent, Observable, Natural, Predictable, Testable, and Tentative (CONPTT)

Theories are only valuable insofar as they can be falsified: this relates to testability (it's essentially the same thing). If a theory can't be falsified (for example, it's impossible to prove that there is no god), then it's not science (in this example case, we call it "religion").