There’s a surprising amount of debate through the years on this, much of which was rehashed as the groups developed the NGSS, the Next Generation Science Standards.

Traditionally, a science education was defined in terms of what you know. The more current definition of a science education splits half in terms of content knowledge and have in terms of science skills or “habits of mind.”  The new standards dramatically reduce the list of facts that students were supposed to know in favor of larger big ideas and skills that students should have mastered.  There is also a tendency to focus on including engineering, career information, and cross curricular skill building

To quote the NGSS doc directly:

The National Research Council’s (NRC) Framework describes a vision of what it means to be proficient in science; it rests on a view of science as both a body of knowledge and an evidence-based, model and theory building enterprise that continually extends, refines, and revises knowledge. It presents three dimensions that will be combined to form each standard:

Dimension 1: Practices:  The practices describe behaviors that scientists engage in as they investigate and build models and theories about the natural world and the key set of engineering practices that engineers use as they design and build models and systems

Dimension 2: Crosscutting Concepts:  Crosscutting concepts have application across all domains of science.

Dimension 3: Disciplinary Core IdeasDisciplinary core ideas have the power to focus K–12 science curriculum, instruction and assessments on the most important aspects of science.