Science
Science is essentially the systematic investigation of nature. Science as an ongoing activity can be considered a cultural behaviour with a focus on nature.
There are aspects of science which can be considered 'natural' for example classification and explanations of natural objects. These are so-called natural sciences.
To do science requires some technological skills, in particular, writing and recording of observations often from measuring instruments compared with calibrated standards and using mathematics to describe or predict observations.
Science is about providing an explanation for 'How things happen'. How does a light bulb work or how does the sun work? for example. Or how do trees grow?, how does a cell form? Science is able to provide models of explanations that are testable , observable or measurable.
A ruler represents a key feature of science. Can it be measured? image: wikipedia
Is all about how atoms and molecules interact and the process that explain and describe them.
An acid base reaction is a typical chemistry investigation showing pH changes and volume. image: wikipedia
Is about how things move on the most basic or fundamental level. From the very large to the very small and the energy transfers between them.
A laser investigation is a typical physics investigation. image: wikipedia/NASA
Is about the processes that describe rock and mineral formation and how they interact from a physical or chemical perspective.
A piece of weathered limestone highlights a geological process. image: R.Conan-Davies
Is about studying living processes of organisms such as plants and animals, or areas of study such as zoology or botany
Sometimes these areas are described in terms of '[topic] sciences' for example
Planetary Sciences ( often considered as part of astronomy) or Earth Sciences
Chemical Sciences (see also chemistry)
Life Sciences (see also biology)
Commentary
In this context [Topic] Sciences often implies the use of other scientific fields of study or techniques to add to the topic. For example Life Sciences would be considered multidisciplinary because it may include physics techniques and topics to add to the investigation of life processes. Often it would include applied aspects such as potential medical applications.