Finito is an informal way to say "finished." After completing a particularly difficult assignment for your English class, you might close your laptop and say, "Finito!"
Finito is commonly used for something that's come to an end, which might confuse a native Spanish speaker. In Spanish, finito means "fine or delicate," though it does mean "finished" in Italian. When you need a fun, slangy way to say "I'm done" or "it's finally over," go ahead and use finito. Cross the finish line after running a 5K? Finito! Graduate from high school? Finito! Finish an entire bag of cheese puffs? Finito!