Encyclicals are papal letters sent to all bishops of the Roman Catholic Church. Encyclicals are letters of pastoral or theological content, meant to be read by all of the faithful.
Apostolic Exhortations are addresses emphatically urging the faithful to consider a particular spiritual matter or activity, of importance to the Pontiff. Despite the similarities, apostolic exhortations carry less authority than encyclicals, and are not considered legislative.
(from The Torch, Boston College's Catholic Newspaper, https://bctorch.com/2020/04/01/a-pocket-guide-for-different-papal-documents/)