It’s a time management method created by Francesco Cirillo. Basically it’s picking a task, doing it for 25 minutes, then taking a 5 minute break. It started when he was a university student struggling to get through reading for his sociology class and started using a timer just trying to hold focus for two minutes at the start. The kitchen timer he used was shaped like a tomato, or pomodoro in Italian as you stated.

[–] dependencyinjection@discuss.tchncs.de 2 points 2 weeks ago

As the other person says it a productivity technique where you might set a timer constraint of 55 / 5. Meaning work for 55 mins and then take a 5 minute break. Rinse and repeat.