Hidden Curriculum: This refers to the unwritten, unofficial, and often unintended lessons, values, behaviors, and perspectives that students learn simply by attending school and participating in the school environment.
These are implicitly communicated through school rules, teacher attitudes, peer interactions, and the general institutional culture rather than explicit academic lesson plans.
Spiral curriculum involves revisiting core concepts at increasing levels of complexity over time.
Core curriculum consists of a central set of required subjects or courses that all students must take.
Concentric curriculum expands outwards from a central, simple theme into broader related concepts.