Science is an approach, a methodology. In short, it is a way to study the world around us. In that sense, it is philosophy. Science is not a set of knowledge, although it is often confused as such. Science is the knowledge generated using a specific method. Here, the term "specific method" is not the most definitive, because different areas of scientific research depend on different approaches. The power and limitations of the methods associated with spectral analysis of distant galaxies is distinct from the power and limitations of the methods associated with transcriptional profiling analysis of organismal responses.
Regardless, there are terms associated with science and terms dissociated with science. Here, are my thoughts.
Associated with science:
Fact: This is a point of reality. A fact is something that is. Generally, scientists do not use the term fact in articles, but do use the term observation or data. Facts are objective. "The basketball hoop is high." While this may seem like a fact, it is not because it is subjective. From my vantage point the hoop is high, but from Manute Bol's perspective it is not. Now if we say "The baskbetball hoop is 10 feet off the ground." That is a fact. This leads to another aspect of facts, they must be verifiable and/or reproducible. If I say the basketball hoop is high, you cannot confirm that because the term high is subjective. However, if I say the hoop is 10 feet high, we can measure it and check. You do not have to take my word for it.
One thing to realize, regardless of whether you care about science or not (and you do even if you dont know it), is that people often speak about facts or in a way that sounds factual without that being the case. For example, "Our intelligence shows Sadam has weapons of mass destruction." (verifiability issues) or "Men are better in math and science than women." (objectivity issues) "4/5 dentists surveyed prefer Dentyne." (reproducibility and objectivity issues).