What does friends of friends on Facebook mean?

[Lttleredrose]

if I post something I know my friends can see it but can their friends see it to?can their friends like and comment on my posts?

[?]

Its your friends, friends. Yes they are able to see them, and probably can comment/like

[Payton]

It means that somebody that you are friends with is friends with that same person. Only it normally says mutual friends. And they shouldn't be able too, it just depends on if you have your profile set on private or not. I recommend setting it on private.

[Karen]

Yes your friends of friends can see, like and comment on but still it depends on how custom you have set your privacy sharing or visibility preference settings.