yes, each team has 2 cars and 2 main drivers who drive those cars in each race. they also will each have one reserve driver who travels to races with them in case something prevents a driver from competing (illness and a penalty have both been reasons that happened this season). that reserve driver is sometimes an active f2 driver and they’re free to compete in f2 unless they’re racing f1 as a sub that weekend! all the f2 races happen on the same weekends and at the same tracks as the f1 races (just not every weekend of the season) so it’s very easy for a reserve driver to participate in f2 while also being available for f1. and teams will usually have a main reserve driver but also like… back ups who also do reserve driver duties like sim work and promo stuff on race weekends… honestly its a bit confusing but many junior drivers are affiliated with a team’s academy and thus may get called in for various team surrogate responsibilities even if they aren’t like The reserve driver!

it’s definitely the case that f1 drivers who once had a seat have ended up being reserve drivers when they lost it… danny ric was the third driver at red bull for half of 2023 after losing his mclaren drive, for example… but it’s not really common, most of the time a driver who loses his seat goes and races in a different series entirely or retires or moves on in some other way!

hope this was helpful and correct lmao