Lag

In online gaming, a lag is a noticeable delay between the action of players and the reaction of the server.

This leads to unexpected teleports, so players aren't actually there where they see themselves. Due to that, unintended and unexpected crashes into e.g. walls or other karts can happen and a player loses time and maybe even the race because of this. Lags are especially unwanted on Ranked or in any other kind of competetive gaming.

Lags appear particularly when having a high ping, means being far away from the server.