This is the 502nd most frequent Finnish word.
twitterissä
"On Twitter."
In this sentence, 'twitterissä' indicates the place where the news is found, functioning as a locative adverb specifying the platform Twitter.
Twitterissä on paljon mielenkiintoisia uutisia.
There are many interesting news pieces on Twitter.
Here, 'twitterissä' is used to describe the mode of communication, indicating the medium through which the learning interaction took place.
Opin ystävältäni Twitterissä, miten valmistaa herkullista leipää.
I learned from my friend on Twitter how to bake delicious bread.
In this case, 'twitterissä' acts as a specifier for the platform used for communication in the interaction described.