The Witcher 3 journal, in full
The Witcher 3 keeps a journal on everyone Geralt meets and rewrites it as the story moves. This is all of it, main characters and the secondary cast, with every entry the journal holds for them.
The later entries give away the plot, so they stay collapsed until you open them. For the story itself rather than the people in it, see the Witcher 3 story so far.
Why Witcher 3 journal entries change
A journal entry is rewritten as quests resolve, which means the same character can carry several versions of the same paragraph. Reading them in order shows what The Witcher 3 knew about someone at each point rather than a single summary written at the end.
Characters who hand out work are worth cross-checking against the Witcher 3 quests page, since the quest entry usually names the reward the conversation does not.