Lore
Lore are categories of items inroduced in the Forsaken expansion of Destiny 2 in the form of lore books. It was initially found in the Triumphs page before it was moved to Collections page with the introduction of Lightfall.
Introduction
Lore pages can unlocked by finding collectables, listening to radio messages or completing certain tasks. Lore books are divided into 3 category, but a 4th category was added with Lightfall's release.
The Vanguard
This category was recently introduced and intended to explain the setting of the Destiny universe. The lore books within this category are unlocked by promoting to the next Guardian Rank.
The Light
This category primarily discusses the nature of the Light and the various entities connected to it.
Dusk and Dawn
This category focuses on entities that are neither aligned with the Light nor the Darkness.
The Darkness
This category primarily discusses the nature of the Darkness and the various entities connected to it.