Zibaldone
Origin
An Italian term meaning "a heap of things," "a miscellany."
While others might have kept similar notebooks, the term is overwhelmingly associated with Giacomo Leopardi's monumental work.
Primary Focus
More of an intellectual diary, a vast repository of Leopardi's own thoughts, philosophical musings, linguistic observations, literary sketches, personal reflections, drafts, lists, and notes on his readings. It was his "intellectual workshop."
Structure And Organisation
Leopardi's Zibaldone di pensieri (Notebook of Thoughts) is famously sprawling and diverse, initially with less overt structure, though he did create an index later. It reads more like a chronological accumulation of a mind at work, a "hot" collection of immediate thoughts and developments.
Intent/Purpose
To record an incredibly wide range of thoughts and observations as they occurred, to explore ideas, to serve as raw material for his poetry and philosophical works, and to document his intellectual and linguistic research. It was a space for generating ideas as much as recording them.