* Observation involves gathering information about the natural world through our senses or through scientific tools. This includes making measurements, collecting data, and conducting experiments.

* Explanation involves developing theories and models to explain the observations we make. This includes identifying patterns, proposing hypotheses, and testing them through further observation and experimentation.

These two parts are intertwined, as observations provide the foundation for explanations, and explanations guide further observations. This cycle of observation and explanation is what drives scientific progress.