Walking in basketball is a dribbling violation that occurs when a player illegally moves with possession of the ball, like when a player moves their pivot foot or moves without dribbling. A walking violation results in a turnover. Walking can also be referred to as traveling.
Anytime a player that has possession of the ball moves without dribbling, they have committed a walking violation. There are a few other special cases that are also considered walking:
If you watch an NCAA or NBA-level game, you will most likely see players take more than the two allotted steps (without dribbling) when they are driving to the basket. This has recently started happening more and more often, but referees are still not calling many walking violations during these games. Referees agree that they are walks after the fact, but during a fast-paced game they may be harder to spot. Fans, players, and coaches have all voiced complaints about the lack of calls, but human error and missed calls will always be parts of the game!