Are groups on Facebook private?

[C]

I joined a Doctor Who group (yea, that's right I'm a Whovian xD) and I want to like pictures that people post in the group. But Facebook shows EVERY single photo you like to the world, for an example: I like a funny post, and it shows up on my newsfeed saying "Carly liked a photo." I hate it does this! And Doctor Who has a lot of aliens and posts that only Whovians would understand, so I don't want my friends (who have no idea what Doctor Who even is) being like "What the heck is this girl liking?" So are groups private, and is there a way to not have Facebook telling everyone what I like or commented on? Don't worry, I don't like or comment on anything bad, just I don't know it's annoying like who gives a crap on what you like or comment on!?! Lol, so thanks for helping, if you can

[abraXus]

there is no way to disable that from happening - but it all depends on the group's settings, not your settings

some groups are private and some are public

the owner of the group conrols that

[confused composing]

Any post, comment & like on an OPEN Group is open for public, so it might show in your friends' Newsfeed.(depends on FB algorithm for every people's Newsfeed).

Knowing that is the characteristic of Open Group, you adjust yourself.

It does not happened to Close & Secret Group as clearly suggested by the name.