This is the 709th most frequent Turkish word.
anlatan
"Anlatan" means "one who explains" or "narrator."
The word 'anlatan' is used as an attributive participle, modifying 'eserdir' to indicate that the work is narrating a story.
Bu roman, bir çocuğun hayat hikayesini anlatan bir eserdir.
This novel is a work that narrates the life story of a child.
In this case, 'anlatan' qualifies 'mektup' by showing the content of the letter which recounts past experiences.
Annem, eski günlerde yaşadıklarını anlatan bir mektup yazmış.
My mother wrote a letter recounting her experiences from the old days.
Here, 'anlatan' describes 'seminar' by indicating that the seminar is providing explanation on a specific topic.