Memories is a set of 6 addons. They write down what happens to each character: sessions, travel, deaths, progress, kills, gathering, loot, money, skills, groups and PvP. The data stays in the game's saved files on your computer until you choose to upload it.
Memories
Sessions, the position trail, progress (levels, XP, quests, discoveries, rest), deaths, close calls, travel (zones, flights, boats, hearthstone, summons, portals, mounts), dungeons and bosses, screenshots, and lines from other addons. This is the core addon and it is always on.
Memories_Combat
Kills, rare kills and long fights.
Memories_Gathering
Gathering, fishing, opening containers and chests, and pick pocket.
Memories_Character
Skills, spells, recipes, talents, consumables, tamed pets, reputation, accepted quests, homes, flight paths and books.
Memories_Economy
Loot, group rolls, gear, equipped items, money, trainers, the auction house, mail and trade.
Memories_Social
Group members, your guild, enemy players, PvP kills and deaths, honor, duels, battlegrounds and PvP rank.
The core addon, Memories, is always needed. You can turn each other addon off in the AddOn list to stop its recording.