If you join a group or follow a page, then your posts on that group are posted with the group settings.
Is it a page or a group?
Pages
Privacy: Page information and posts are public and generally available to everyone on Facebook.
Audience: Anyone can like a Page to connect with it and get News Feed updates. There is no limit to how many people can like a Page.
Communication: People who help manage a Page can share posts from the Page. Page posts can appear in the News Feeds of people who like the Page. Page owners can also create customized apps for their Page and check Page Insights to track the Page’s growth and activity.
Groups
Privacy: In addition to a public setting, more privacy settings are available for groups. In secret and closed groups, posts are only visible to group members.
Audience: You can adjust group privacy to require members to be approved or added by admins. When a group reaches a certain size, some features are limited. The most useful groups tend to be the ones you create with small groups of people you know.
Communication: In groups, members receive notifications by default when any member posts in the group. Group members can participate in chats, upload photos to shared albums, collaborate on group docs and invite members who are friends to group events.
What are the privacy options for groups?
There are 3 privacy options for groups: Public, Closed and Secret. The table below shows who can join these groups and what people can see about them.
Public Closed Secret
Who can join?
Public Anyone can join or be added or invited by a member
Closed Anyone can ask to join or be added or invited by a member
Secret Anyone, but they have to be added or invited by a member
Who can see the group's name?
public Anyone
Closed Anyone
Secret Current and former members
Who can see who's in the group?
public Anyone
closed Anyone
Secret Only current members
Who can see the group description?
public Anyone
closed Anyone
secret Current and former members
Who can see the group tags?
public Anyone
closed Anyone
secret Current and former members
Who can see what members post in the group?
public Anyone
closed Only current members
secret Only current members
Who can find the group in search?
public Anyone
closed Anyone
secret Current and former members
Who can see stories about the group on Facebook (like in News Feed and search)?
public Anyone
closed Only current members
secret Only current members