During service, a "push" or a "pop" or a "hit" is a time period where a large number of tickets come in. As you learn the ebbs an flows of your own kitchen you will be able to anticipate a hit and prepare accordingly. For instance if you know that the height of the first turn is at 7:30 then you know to always be ready with full mise - squeeze bottles, backups of key compnents in your lowboy, proteins cooked off and sandbaged so you can withstand the pop.
It could also be one station that gets hit. The sauté guy or the pasta gal could have a dispraportionally worse night than the rest of the cooks if everyone in the dining room seems to be ordering the same thing.
Expediting Chef during preshift: "It's Saturday night in New York City, so it's going to be a busy one. We're starting at 280 covers so make sure you're ready. We're getting hit right off the bat at 5:00. 50 diners are seating. We have another hit coming at 7:00 and a full second turn starting at 8:00. If there's side projects you need done during service, speak now or forever hold your peace. You need to be dug in for a busy service. I don't want to see anyone going offline to get something from the walkin or from downstairs."
Grill Cook: "How was your night"
Garmo: "We got lit up during that first push. All tuna carpachio and steak tartare. Those take forever to plate so we stayed busy."