okay!👍
first, it's kinda informal equivalent of english conjunctive "that" as "he said that...「彼は...って言った」" or "do you know that...「...って知ってる?」" which was derived from its formal form 「~と」「~ということを」
second, it can be attached just after a noun to emphasize it is the theme. 「これって何?」(≒これは何ですか?)"(speaking of this,) what is it?"
there may be some other usages but basically these two are common.